Text file src/cmd/compile/internal/ssa/_gen/RISCV64.rules

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Lowering arithmetic
     6  (Add(Ptr|64|32|16|8) ...) => (ADD ...)
     7  (Add(64|32)F ...) => (FADD(D|S) ...)
     8  
     9  (Sub(Ptr|64|32|16|8) ...) => (SUB ...)
    10  (Sub(64|32)F ...) => (FSUB(D|S) ...)
    11  
    12  (Mul64 ...) => (MUL  ...)
    13  (Mul64uhilo ...) => (LoweredMuluhilo ...)
    14  (Mul64uover ...) => (LoweredMuluover ...)
    15  (Mul32 ...) => (MULW ...)
    16  (Mul16 x y) => (MULW (SignExt16to32 x) (SignExt16to32 y))
    17  (Mul8 x y)  => (MULW (SignExt8to32 x)  (SignExt8to32 y))
    18  (Mul(64|32)F ...) => (FMUL(D|S) ...)
    19  
    20  (Div(64|32)F ...) => (FDIV(D|S) ...)
    21  
    22  (Div64 x y [false])  => (DIV x y)
    23  (Div64u ...) => (DIVU ...)
    24  (Div32 x y [false])  => (DIVW x y)
    25  (Div32u ...) => (DIVUW ...)
    26  (Div16 x y [false])  => (DIVW  (SignExt16to32 x) (SignExt16to32 y))
    27  (Div16u x y) => (DIVUW (ZeroExt16to32 x) (ZeroExt16to32 y))
    28  (Div8 x y)   => (DIVW  (SignExt8to32 x)  (SignExt8to32 y))
    29  (Div8u x y)  => (DIVUW (ZeroExt8to32 x)  (ZeroExt8to32 y))
    30  
    31  (Hmul64 ...)  => (MULH  ...)
    32  (Hmul64u ...) => (MULHU ...)
    33  (Hmul32 x y)  => (SRAI [32] (MUL  (SignExt32to64 x) (SignExt32to64 y)))
    34  (Hmul32u x y) => (SRLI [32] (MUL  (ZeroExt32to64 x) (ZeroExt32to64 y)))
    35  
    36  (Select0 (Add64carry x y c)) => (ADD (ADD <typ.UInt64> x y) c)
    37  (Select1 (Add64carry x y c)) =>
    38  	(OR (SLTU <typ.UInt64> s:(ADD <typ.UInt64> x y) x) (SLTU <typ.UInt64> (ADD <typ.UInt64> s c) s))
    39  
    40  (Select0 (Sub64borrow x y c)) => (SUB (SUB <typ.UInt64> x y) c)
    41  (Select1 (Sub64borrow x y c)) =>
    42  	(OR (SLTU <typ.UInt64> x s:(SUB <typ.UInt64> x y)) (SLTU <typ.UInt64> s (SUB <typ.UInt64> s c)))
    43  
    44  // (x + y) / 2 => (x / 2) + (y / 2) + (x & y & 1)
    45  (Avg64u <t> x y) => (ADD (ADD <t> (SRLI <t> [1] x) (SRLI <t> [1] y)) (ANDI <t> [1] (AND <t> x y)))
    46  
    47  (Mod64 x y [false])  => (REM x y)
    48  (Mod64u ...) => (REMU  ...)
    49  (Mod32 x y [false])  => (REMW x y)
    50  (Mod32u ...) => (REMUW ...)
    51  (Mod16 x y [false])  => (REMW  (SignExt16to32 x) (SignExt16to32 y))
    52  (Mod16u x y) => (REMUW (ZeroExt16to32 x) (ZeroExt16to32 y))
    53  (Mod8 x y)   => (REMW  (SignExt8to32  x) (SignExt8to32  y))
    54  (Mod8u x y)  => (REMUW (ZeroExt8to32  x) (ZeroExt8to32  y))
    55  
    56  (And(64|32|16|8) ...) => (AND ...)
    57  (Or(64|32|16|8) ...) => (OR ...)
    58  (Xor(64|32|16|8) ...) => (XOR ...)
    59  
    60  (Neg(64|32|16|8) ...) => (NEG ...)
    61  (Neg(64|32)F ...) => (FNEG(D|S) ...)
    62  
    63  (Com(64|32|16|8) ...) => (NOT ...)
    64  
    65  
    66  (Sqrt ...) => (FSQRTD ...)
    67  (Sqrt32 ...) => (FSQRTS ...)
    68  
    69  (Copysign ...) => (FSGNJD ...)
    70  
    71  (Abs ...) => (FABSD ...)
    72  
    73  (FMA ...) => (FMADDD ...)
    74  
    75  (Min(64|32)F ...) => (LoweredFMIN(D|S) ...)
    76  (Max(64|32)F ...) => (LoweredFMAX(D|S) ...)
    77  
    78  // Sign and zero extension.
    79  
    80  (SignExt8to16  ...) => (MOVBreg ...)
    81  (SignExt8to32  ...) => (MOVBreg ...)
    82  (SignExt8to64  ...) => (MOVBreg ...)
    83  (SignExt16to32 ...) => (MOVHreg ...)
    84  (SignExt16to64 ...) => (MOVHreg ...)
    85  (SignExt32to64 ...) => (MOVWreg ...)
    86  
    87  (ZeroExt8to16  ...) => (MOVBUreg ...)
    88  (ZeroExt8to32  ...) => (MOVBUreg ...)
    89  (ZeroExt8to64  ...) => (MOVBUreg ...)
    90  (ZeroExt16to32 ...) => (MOVHUreg ...)
    91  (ZeroExt16to64 ...) => (MOVHUreg ...)
    92  (ZeroExt32to64 ...) => (MOVWUreg ...)
    93  
    94  (Cvt32to32F ...) => (FCVTSW ...)
    95  (Cvt32to64F ...) => (FCVTDW ...)
    96  (Cvt64to32F ...) => (FCVTSL ...)
    97  (Cvt64to64F ...) => (FCVTDL ...)
    98  
    99  (Cvt32Fto32 ...) => (FCVTWS ...)
   100  (Cvt32Fto64 ...) => (FCVTLS ...)
   101  (Cvt64Fto32 ...) => (FCVTWD ...)
   102  (Cvt64Fto64 ...) => (FCVTLD ...)
   103  
   104  (Cvt32Fto64F ...) => (FCVTDS ...)
   105  (Cvt64Fto32F ...) => (FCVTSD ...)
   106  
   107  (CvtBoolToUint8 ...) => (Copy ...)
   108  
   109  (Round(32|64)F ...) => (LoweredRound(32|64)F ...)
   110  
   111  (Slicemask <t> x) => (SRAI [63] (NEG <t> x))
   112  
   113  // Truncations
   114  // We ignore the unused high parts of registers, so truncates are just copies.
   115  (Trunc16to8  ...) => (Copy ...)
   116  (Trunc32to8  ...) => (Copy ...)
   117  (Trunc32to16 ...) => (Copy ...)
   118  (Trunc64to8  ...) => (Copy ...)
   119  (Trunc64to16 ...) => (Copy ...)
   120  (Trunc64to32 ...) => (Copy ...)
   121  
   122  // Shifts
   123  
   124  // SLL only considers the bottom 6 bits of y. If y > 64, the result should
   125  // always be 0.
   126  //
   127  // Breaking down the operation:
   128  //
   129  // (SLL x y) generates x << (y & 63).
   130  //
   131  // If y < 64, this is the value we want. Otherwise, we want zero.
   132  //
   133  // So, we AND with -1 * uint64(y < 64), which is 0xfffff... if y < 64 and 0 otherwise.
   134  (Lsh8x8   <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   135  (Lsh8x16  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   136  (Lsh8x32  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   137  (Lsh8x64  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] y)))
   138  (Lsh16x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   139  (Lsh16x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   140  (Lsh16x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   141  (Lsh16x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] y)))
   142  (Lsh32x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   143  (Lsh32x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   144  (Lsh32x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   145  (Lsh32x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] y)))
   146  (Lsh64x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   147  (Lsh64x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   148  (Lsh64x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   149  (Lsh64x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] y)))
   150  
   151  (Lsh8x(64|32|16|8)  x y) && shiftIsBounded(v) => (SLL x y)
   152  (Lsh16x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   153  (Lsh32x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   154  (Lsh64x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   155  
   156  // SRL only considers the bottom 6 bits of y, similarly SRLW only considers the
   157  // bottom 5 bits of y. Ensure that the result is always zero if the shift exceeds
   158  // the maximum value. See Lsh above for a detailed description.
   159  (Rsh8Ux8   <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   160  (Rsh8Ux16  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   161  (Rsh8Ux32  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   162  (Rsh8Ux64  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] y)))
   163  (Rsh16Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   164  (Rsh16Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   165  (Rsh16Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   166  (Rsh16Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] y)))
   167  (Rsh32Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt8to64  y))))
   168  (Rsh32Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt16to64 y))))
   169  (Rsh32Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt32to64 y))))
   170  (Rsh32Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] y)))
   171  (Rsh64Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   172  (Rsh64Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   173  (Rsh64Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   174  (Rsh64Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] y)))
   175  
   176  (Rsh8Ux(64|32|16|8)  x y) && shiftIsBounded(v) => (SRL  (ZeroExt8to64  x) y)
   177  (Rsh16Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRL  (ZeroExt16to64 x) y)
   178  (Rsh32Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRLW x                 y)
   179  (Rsh64Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRL  x                 y)
   180  
   181  // SRA only considers the bottom 6 bits of y, similarly SRAW only considers the
   182  // bottom 5 bits. If y is greater than the maximum value (either 63 or 31
   183  // depending on the instruction),  the result of the shift should be either 0
   184  // or -1 based on the sign bit of x.
   185  //
   186  // We implement this by performing the max shift (-1) if y > the maximum value.
   187  //
   188  // We OR (uint64(y < 64) - 1) into y before passing it to SRA. This leaves
   189  // us with -1 (0xffff...) if y >= 64.  Similarly, we OR (uint64(y < 32) - 1) into y
   190  // before passing it to SRAW.
   191  //
   192  // We don't need to sign-extend the OR result, as it will be at minimum 8 bits,
   193  // more than the 5 or 6 bits SRAW and SRA care about.
   194  (Rsh8x8   <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   195  (Rsh8x16  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   196  (Rsh8x32  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   197  (Rsh8x64  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   198  (Rsh16x8  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   199  (Rsh16x16 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   200  (Rsh16x32 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   201  (Rsh16x64 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   202  (Rsh32x8  <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt8to64  y)))))
   203  (Rsh32x16 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt16to64 y)))))
   204  (Rsh32x32 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt32to64 y)))))
   205  (Rsh32x64 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] y))))
   206  (Rsh64x8  <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   207  (Rsh64x16 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   208  (Rsh64x32 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   209  (Rsh64x64 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   210  
   211  (Rsh8x(64|32|16|8)  x y) && shiftIsBounded(v) => (SRA  (SignExt8to64  x) y)
   212  (Rsh16x(64|32|16|8) x y) && shiftIsBounded(v) => (SRA  (SignExt16to64 x) y)
   213  (Rsh32x(64|32|16|8) x y) && shiftIsBounded(v) => (SRAW  x                y)
   214  (Rsh64x(64|32|16|8) x y) && shiftIsBounded(v) => (SRA   x                y)
   215  
   216  // Rotates.
   217  (RotateLeft8  <t> x y) => (OR (SLL  <t> x (ANDI [7]  <y.Type> y)) (SRL <t> (ZeroExt8to64  x) (ANDI [7]  <y.Type> (NEG <y.Type> y))))
   218  (RotateLeft16 <t> x y) => (OR (SLL  <t> x (ANDI [15] <y.Type> y)) (SRL <t> (ZeroExt16to64 x) (ANDI [15] <y.Type> (NEG <y.Type> y))))
   219  (RotateLeft32 ...) => (ROLW ...)
   220  (RotateLeft64 ...) => (ROL  ...)
   221  
   222  (Less64  ...) => (SLT  ...)
   223  (Less32  x y) => (SLT  (SignExt32to64 x) (SignExt32to64 y))
   224  (Less16  x y) => (SLT  (SignExt16to64 x) (SignExt16to64 y))
   225  (Less8   x y) => (SLT  (SignExt8to64  x) (SignExt8to64  y))
   226  (Less64U ...) => (SLTU ...)
   227  (Less32U x y) => (SLTU (ZeroExt32to64 x) (ZeroExt32to64 y))
   228  (Less16U x y) => (SLTU (ZeroExt16to64 x) (ZeroExt16to64 y))
   229  (Less8U  x y) => (SLTU (ZeroExt8to64  x) (ZeroExt8to64  y))
   230  (Less(64|32)F ...) => (FLT(D|S) ...)
   231  
   232  // Convert x <= y to !(y > x).
   233  (Leq(64|32|16|8)  x y) => (Not (Less(64|32|16|8)  y x))
   234  (Leq(64|32|16|8)U x y) => (Not (Less(64|32|16|8)U y x))
   235  (Leq(64|32)F ...) => (FLE(D|S) ...)
   236  
   237  (EqPtr x y) => (SEQZ (SUB <typ.Uintptr> x y))
   238  (Eq64  x y) => (SEQZ (SUB <x.Type> x y))
   239  (Eq32  x y) &&  x.Type.IsSigned() => (SEQZ (SUB <x.Type> (SignExt32to64 x) (SignExt32to64 y)))
   240  (Eq32  x y) && !x.Type.IsSigned() => (SEQZ (SUB <x.Type> (ZeroExt32to64 x) (ZeroExt32to64 y)))
   241  (Eq16  x y) => (SEQZ (SUB <x.Type> (ZeroExt16to64 x) (ZeroExt16to64 y)))
   242  (Eq8   x y) => (SEQZ (SUB <x.Type> (ZeroExt8to64  x) (ZeroExt8to64  y)))
   243  (Eq(64|32)F ...) => (FEQ(D|S) ...)
   244  
   245  (NeqPtr x y) => (Not (EqPtr x y))
   246  (Neq64  x y) => (Not (Eq64  x y))
   247  (Neq32  x y) => (Not (Eq32  x y))
   248  (Neq16  x y) => (Not (Eq16  x y))
   249  (Neq8   x y) => (Not (Eq8   x y))
   250  (Neq(64|32)F ...) => (FNE(D|S) ...)
   251  
   252  // Loads
   253  (Load <t> ptr mem) &&  t.IsBoolean()                   => (MOVBUload ptr mem)
   254  (Load <t> ptr mem) && ( is8BitInt(t) &&  t.IsSigned()) => (MOVBload  ptr mem)
   255  (Load <t> ptr mem) && ( is8BitInt(t) && !t.IsSigned()) => (MOVBUload ptr mem)
   256  (Load <t> ptr mem) && (is16BitInt(t) &&  t.IsSigned()) => (MOVHload  ptr mem)
   257  (Load <t> ptr mem) && (is16BitInt(t) && !t.IsSigned()) => (MOVHUload ptr mem)
   258  (Load <t> ptr mem) && (is32BitInt(t) &&  t.IsSigned()) => (MOVWload  ptr mem)
   259  (Load <t> ptr mem) && (is32BitInt(t) && !t.IsSigned()) => (MOVWUload ptr mem)
   260  (Load <t> ptr mem) && (is64BitInt(t) || isPtr(t))      => (MOVDload  ptr mem)
   261  (Load <t> ptr mem) &&  is32BitFloat(t)                 => (FMOVWload ptr mem)
   262  (Load <t> ptr mem) &&  is64BitFloat(t)                 => (FMOVDload ptr mem)
   263  
   264  // Stores
   265  (Store {t} ptr val mem) && t.Size() == 1 => (MOVBstore ptr val mem)
   266  (Store {t} ptr val mem) && t.Size() == 2 => (MOVHstore ptr val mem)
   267  (Store {t} ptr val mem) && t.Size() == 4 && !t.IsFloat() => (MOVWstore ptr val mem)
   268  (Store {t} ptr val mem) && t.Size() == 8 && !t.IsFloat() => (MOVDstore ptr val mem)
   269  (Store {t} ptr val mem) && t.Size() == 4 &&  t.IsFloat() => (FMOVWstore ptr val mem)
   270  (Store {t} ptr val mem) && t.Size() == 8 &&  t.IsFloat() => (FMOVDstore ptr val mem)
   271  
   272  // We need to fold MOVaddr into the LD/MOVDstore ops so that the live variable analysis
   273  // knows what variables are being read/written by the ops.
   274  (MOVBUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   275  	(MOVBUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   276  (MOVBload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   277  	(MOVBload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   278  (MOVHUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   279  	(MOVHUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   280  (MOVHload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   281  	(MOVHload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   282  (MOVWUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   283  	(MOVWUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   284  (MOVWload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   285  	(MOVWload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   286  (MOVDload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   287  	(MOVDload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   288  
   289  (MOVBstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   290  	(MOVBstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   291  (MOVHstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   292  	(MOVHstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   293  (MOVWstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   294  	(MOVWstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   295  (MOVDstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   296  	(MOVDstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   297  (MOVBstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   298  	(MOVBstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   299  (MOVHstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   300  	(MOVHstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   301  (MOVWstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   302  	(MOVWstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   303  (MOVDstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   304  	(MOVDstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   305  
   306  (MOVBUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   307  	(MOVBUload [off1+int32(off2)] {sym} base mem)
   308  (MOVBload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   309  	(MOVBload  [off1+int32(off2)] {sym} base mem)
   310  (MOVHUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   311  	(MOVHUload [off1+int32(off2)] {sym} base mem)
   312  (MOVHload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   313  	(MOVHload  [off1+int32(off2)] {sym} base mem)
   314  (MOVWUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   315  	(MOVWUload [off1+int32(off2)] {sym} base mem)
   316  (MOVWload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   317  	(MOVWload  [off1+int32(off2)] {sym} base mem)
   318  (MOVDload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   319  	(MOVDload  [off1+int32(off2)] {sym} base mem)
   320  
   321  (MOVBstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   322  	(MOVBstore [off1+int32(off2)] {sym} base val mem)
   323  (MOVHstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   324  	(MOVHstore [off1+int32(off2)] {sym} base val mem)
   325  (MOVWstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   326  	(MOVWstore [off1+int32(off2)] {sym} base val mem)
   327  (MOVDstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   328  	(MOVDstore [off1+int32(off2)] {sym} base val mem)
   329  (MOVBstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVBstorezero [off1+int32(off2)] {sym} ptr mem)
   330  (MOVHstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVHstorezero [off1+int32(off2)] {sym} ptr mem)
   331  (MOVWstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVWstorezero [off1+int32(off2)] {sym} ptr mem)
   332  (MOVDstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVDstorezero [off1+int32(off2)] {sym} ptr mem)
   333  
   334  // Similarly, fold ADDI into MOVaddr to avoid confusing live variable analysis
   335  // with OffPtr -> ADDI.
   336  (ADDI [c] (MOVaddr [d] {s} x)) && is32Bit(c+int64(d)) => (MOVaddr [int32(c)+d] {s} x)
   337  
   338  // Small zeroing
   339  (Zero [0] _ mem) => mem
   340  (Zero [1] ptr mem) => (MOVBstore ptr (MOVDconst [0]) mem)
   341  (Zero [2] {t} ptr mem) && t.Alignment()%2 == 0 =>
   342  	(MOVHstore ptr (MOVDconst [0]) mem)
   343  (Zero [2] ptr mem) =>
   344  	(MOVBstore [1] ptr (MOVDconst [0])
   345  		(MOVBstore ptr (MOVDconst [0]) mem))
   346  (Zero [4] {t} ptr mem) && t.Alignment()%4 == 0 =>
   347  	(MOVWstore ptr (MOVDconst [0]) mem)
   348  (Zero [4] {t} ptr mem) && t.Alignment()%2 == 0 =>
   349  	(MOVHstore [2] ptr (MOVDconst [0])
   350  		(MOVHstore ptr (MOVDconst [0]) mem))
   351  (Zero [4] ptr mem) =>
   352  	(MOVBstore [3] ptr (MOVDconst [0])
   353  		(MOVBstore [2] ptr (MOVDconst [0])
   354  			(MOVBstore [1] ptr (MOVDconst [0])
   355  				(MOVBstore ptr (MOVDconst [0]) mem))))
   356  (Zero [8] {t} ptr mem) && t.Alignment()%8 == 0 =>
   357  	(MOVDstore ptr (MOVDconst [0]) mem)
   358  (Zero [8] {t} ptr mem) && t.Alignment()%4 == 0 =>
   359  	(MOVWstore [4] ptr (MOVDconst [0])
   360  		(MOVWstore ptr (MOVDconst [0]) mem))
   361  (Zero [8] {t} ptr mem) && t.Alignment()%2 == 0 =>
   362  	(MOVHstore [6] ptr (MOVDconst [0])
   363  		(MOVHstore [4] ptr (MOVDconst [0])
   364  			(MOVHstore [2] ptr (MOVDconst [0])
   365  				(MOVHstore ptr (MOVDconst [0]) mem))))
   366  
   367  (Zero [3] ptr mem) =>
   368  	(MOVBstore [2] ptr (MOVDconst [0])
   369  		(MOVBstore [1] ptr (MOVDconst [0])
   370  			(MOVBstore ptr (MOVDconst [0]) mem)))
   371  (Zero [6] {t} ptr mem) && t.Alignment()%2 == 0 =>
   372  	(MOVHstore [4] ptr (MOVDconst [0])
   373  		(MOVHstore [2] ptr (MOVDconst [0])
   374  			(MOVHstore ptr (MOVDconst [0]) mem)))
   375  (Zero [12] {t} ptr mem) && t.Alignment()%4 == 0 =>
   376  	(MOVWstore [8] ptr (MOVDconst [0])
   377  		(MOVWstore [4] ptr (MOVDconst [0])
   378  			(MOVWstore ptr (MOVDconst [0]) mem)))
   379  (Zero [16] {t} ptr mem) && t.Alignment()%8 == 0 =>
   380  	(MOVDstore [8] ptr (MOVDconst [0])
   381  		(MOVDstore ptr (MOVDconst [0]) mem))
   382  (Zero [24] {t} ptr mem) && t.Alignment()%8 == 0 =>
   383  	(MOVDstore [16] ptr (MOVDconst [0])
   384  		(MOVDstore [8] ptr (MOVDconst [0])
   385  			(MOVDstore ptr (MOVDconst [0]) mem)))
   386  (Zero [32] {t} ptr mem) && t.Alignment()%8 == 0 =>
   387  	(MOVDstore [24] ptr (MOVDconst [0])
   388  		(MOVDstore [16] ptr (MOVDconst [0])
   389  			(MOVDstore [8] ptr (MOVDconst [0])
   390  				(MOVDstore ptr (MOVDconst [0]) mem))))
   391  
   392  // Medium 8-aligned zeroing uses a Duff's device
   393  // 8 and 128 are magic constants, see runtime/mkduff.go
   394  (Zero [s] {t} ptr mem)
   395  	&& s%8 == 0 && s <= 8*128
   396  	&& t.Alignment()%8 == 0 && !config.noDuffDevice =>
   397  	(DUFFZERO [8 * (128 - s/8)] ptr mem)
   398  
   399  // Generic zeroing uses a loop
   400  (Zero [s] {t} ptr mem) =>
   401  	(LoweredZero [t.Alignment()]
   402  		ptr
   403  		(ADD <ptr.Type> ptr (MOVDconst [s-moveSize(t.Alignment(), config)]))
   404  		mem)
   405  
   406  // Checks
   407  (IsNonNil ...) => (SNEZ ...)
   408  (IsInBounds ...) => (Less64U ...)
   409  (IsSliceInBounds ...) => (Leq64U ...)
   410  
   411  // Trivial lowering
   412  (NilCheck ...) => (LoweredNilCheck ...)
   413  (GetClosurePtr ...) => (LoweredGetClosurePtr ...)
   414  (GetCallerSP ...) => (LoweredGetCallerSP ...)
   415  (GetCallerPC ...) => (LoweredGetCallerPC ...)
   416  
   417  // Write barrier.
   418  (WB ...) => (LoweredWB ...)
   419  
   420  // Publication barrier as intrinsic
   421  (PubBarrier ...) => (LoweredPubBarrier ...)
   422  
   423  (PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
   424  (PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
   425  (PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)
   426  
   427  // Small moves
   428  (Move [0] _ _ mem) => mem
   429  (Move [1] dst src mem) => (MOVBstore dst (MOVBload src mem) mem)
   430  (Move [2] {t} dst src mem) && t.Alignment()%2 == 0 =>
   431  	(MOVHstore dst (MOVHload src mem) mem)
   432  (Move [2] dst src mem) =>
   433  	(MOVBstore [1] dst (MOVBload [1] src mem)
   434  		(MOVBstore dst (MOVBload src mem) mem))
   435  (Move [4] {t} dst src mem) && t.Alignment()%4 == 0 =>
   436  	(MOVWstore dst (MOVWload src mem) mem)
   437  (Move [4] {t} dst src mem) && t.Alignment()%2 == 0 =>
   438  	(MOVHstore [2] dst (MOVHload [2] src mem)
   439  		(MOVHstore dst (MOVHload src mem) mem))
   440  (Move [4] dst src mem) =>
   441  	(MOVBstore [3] dst (MOVBload [3] src mem)
   442  		(MOVBstore [2] dst (MOVBload [2] src mem)
   443  			(MOVBstore [1] dst (MOVBload [1] src mem)
   444  				(MOVBstore dst (MOVBload src mem) mem))))
   445  (Move [8] {t} dst src mem) && t.Alignment()%8 == 0 =>
   446  	(MOVDstore dst (MOVDload src mem) mem)
   447  (Move [8] {t} dst src mem) && t.Alignment()%4 == 0 =>
   448  	(MOVWstore [4] dst (MOVWload [4] src mem)
   449  		(MOVWstore dst (MOVWload src mem) mem))
   450  (Move [8] {t} dst src mem) && t.Alignment()%2 == 0 =>
   451  	(MOVHstore [6] dst (MOVHload [6] src mem)
   452  		(MOVHstore [4] dst (MOVHload [4] src mem)
   453  			(MOVHstore [2] dst (MOVHload [2] src mem)
   454  				(MOVHstore dst (MOVHload src mem) mem))))
   455  
   456  (Move [3] dst src mem) =>
   457  	(MOVBstore [2] dst (MOVBload [2] src mem)
   458  		(MOVBstore [1] dst (MOVBload [1] src mem)
   459  			(MOVBstore dst (MOVBload src mem) mem)))
   460  (Move [6] {t} dst src mem) && t.Alignment()%2 == 0 =>
   461  	(MOVHstore [4] dst (MOVHload [4] src mem)
   462  		(MOVHstore [2] dst (MOVHload [2] src mem)
   463  			(MOVHstore dst (MOVHload src mem) mem)))
   464  (Move [12] {t} dst src mem) && t.Alignment()%4 == 0 =>
   465  	(MOVWstore [8] dst (MOVWload [8] src mem)
   466  		(MOVWstore [4] dst (MOVWload [4] src mem)
   467  			(MOVWstore dst (MOVWload src mem) mem)))
   468  (Move [16] {t} dst src mem) && t.Alignment()%8 == 0 =>
   469  	(MOVDstore [8] dst (MOVDload [8] src mem)
   470  		(MOVDstore dst (MOVDload src mem) mem))
   471  (Move [24] {t} dst src mem) && t.Alignment()%8 == 0 =>
   472  	(MOVDstore [16] dst (MOVDload [16] src mem)
   473  		(MOVDstore [8] dst (MOVDload [8] src mem)
   474  			(MOVDstore dst (MOVDload src mem) mem)))
   475  (Move [32] {t} dst src mem) && t.Alignment()%8 == 0 =>
   476  	(MOVDstore [24] dst (MOVDload [24] src mem)
   477  		(MOVDstore [16] dst (MOVDload [16] src mem)
   478  			(MOVDstore [8] dst (MOVDload [8] src mem)
   479  				(MOVDstore dst (MOVDload src mem) mem))))
   480  
   481  // Medium 8-aligned move uses a Duff's device
   482  // 16 and 128 are magic constants, see runtime/mkduff.go
   483  (Move [s] {t} dst src mem)
   484  	&& s%8 == 0 && s <= 8*128 && t.Alignment()%8 == 0
   485  	&& !config.noDuffDevice && logLargeCopy(v, s) =>
   486  	(DUFFCOPY [16 * (128 - s/8)] dst src mem)
   487  
   488  // Generic move uses a loop
   489  (Move [s] {t} dst src mem) && (s <= 16 || logLargeCopy(v, s)) =>
   490  	(LoweredMove [t.Alignment()]
   491  		dst
   492  		src
   493  		(ADDI <src.Type> [s-moveSize(t.Alignment(), config)] src)
   494  		mem)
   495  
   496  // Boolean ops; 0=false, 1=true
   497  (AndB ...) => (AND ...)
   498  (OrB  ...) => (OR  ...)
   499  (EqB  x y) => (SEQZ (SUB <typ.Bool> x y))
   500  (NeqB x y) => (SNEZ (SUB <typ.Bool> x y))
   501  (Not  ...) => (SEQZ ...)
   502  
   503  // Lowering pointer arithmetic
   504  // TODO: Special handling for SP offsets, like ARM
   505  (OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVaddr [int32(off)] ptr)
   506  (OffPtr [off] ptr) && is32Bit(off) => (ADDI [off] ptr)
   507  (OffPtr [off] ptr) => (ADD (MOVDconst [off]) ptr)
   508  
   509  (Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
   510  (Const32F [val]) => (FMVSX (MOVDconst [int64(math.Float32bits(val))]))
   511  (Const64F [val]) => (FMVDX (MOVDconst [int64(math.Float64bits(val))]))
   512  (ConstNil) => (MOVDconst [0])
   513  (ConstBool [val]) => (MOVDconst [int64(b2i(val))])
   514  
   515  (Addr {sym} base) => (MOVaddr {sym} [0] base)
   516  (LocalAddr <t> {sym} base mem) && t.Elem().HasPointers() => (MOVaddr {sym} (SPanchored base mem))
   517  (LocalAddr <t> {sym} base _)  && !t.Elem().HasPointers() => (MOVaddr {sym} base)
   518  
   519  // Calls
   520  (StaticCall  ...) => (CALLstatic  ...)
   521  (ClosureCall ...) => (CALLclosure ...)
   522  (InterCall   ...) => (CALLinter   ...)
   523  (TailCall ...) => (CALLtail ...)
   524  
   525  // Atomic Intrinsics
   526  (AtomicLoad(Ptr|64|32|8)  ...) => (LoweredAtomicLoad(64|64|32|8) ...)
   527  (AtomicStore(PtrNoWB|64|32|8) ...) => (LoweredAtomicStore(64|64|32|8) ...)
   528  (AtomicAdd(64|32) ...) => (LoweredAtomicAdd(64|32) ...)
   529  
   530  // AtomicAnd8(ptr,val) => LoweredAtomicAnd32(ptr&^3, ^((uint8(val) ^ 0xff) << ((ptr & 3) * 8)))
   531  (AtomicAnd8 ptr val mem) =>
   532  	(LoweredAtomicAnd32 (ANDI <typ.Uintptr> [^3] ptr)
   533  		(NOT <typ.UInt32> (SLL <typ.UInt32> (XORI <typ.UInt32> [0xff] (ZeroExt8to32 val))
   534  			(SLLI <typ.UInt64> [3] (ANDI <typ.UInt64> [3] ptr)))) mem)
   535  
   536  (AtomicAnd32 ...) => (LoweredAtomicAnd32 ...)
   537  
   538  (AtomicCompareAndSwap32 ptr old new mem) => (LoweredAtomicCas32 ptr (SignExt32to64 old) new mem)
   539  (AtomicCompareAndSwap64 ...) => (LoweredAtomicCas64 ...)
   540  
   541  (AtomicExchange(64|32) ...) => (LoweredAtomicExchange(64|32) ...)
   542  
   543  // AtomicOr8(ptr,val)  => LoweredAtomicOr32(ptr&^3, uint32(val)<<((ptr&3)*8))
   544  (AtomicOr8 ptr val mem) =>
   545  	(LoweredAtomicOr32 (ANDI <typ.Uintptr> [^3] ptr)
   546  		(SLL <typ.UInt32> (ZeroExt8to32 val)
   547  			(SLLI <typ.UInt64> [3] (ANDI <typ.UInt64> [3] ptr))) mem)
   548  
   549  (AtomicOr32  ...) => (LoweredAtomicOr32  ...)
   550  
   551  // Conditional branches
   552  (If cond yes no) => (BNEZ (MOVBUreg <typ.UInt64> cond) yes no)
   553  
   554  // Optimizations
   555  
   556  // Absorb SEQZ/SNEZ into branch.
   557  (BEQZ (SEQZ x) yes no) => (BNEZ x yes no)
   558  (BEQZ (SNEZ x) yes no) => (BEQZ x yes no)
   559  (BNEZ (SEQZ x) yes no) => (BEQZ x yes no)
   560  (BNEZ (SNEZ x) yes no) => (BNEZ x yes no)
   561  
   562  // Remove redundant NEG from BEQZ/BNEZ.
   563  (BEQZ (NEG x) yes no) => (BEQZ x yes no)
   564  (BNEZ (NEG x) yes no) => (BNEZ x yes no)
   565  
   566  // Negate comparison with FNES/FNED.
   567  (BEQZ (FNES <t> x y) yes no) => (BNEZ (FEQS <t> x y) yes no)
   568  (BNEZ (FNES <t> x y) yes no) => (BEQZ (FEQS <t> x y) yes no)
   569  (BEQZ (FNED <t> x y) yes no) => (BNEZ (FEQD <t> x y) yes no)
   570  (BNEZ (FNED <t> x y) yes no) => (BEQZ (FEQD <t> x y) yes no)
   571  
   572  // Convert BEQZ/BNEZ into more optimal branch conditions.
   573  (BEQZ (SUB x y) yes no) => (BEQ x y yes no)
   574  (BNEZ (SUB x y) yes no) => (BNE x y yes no)
   575  (BEQZ (SLT x y) yes no) => (BGE x y yes no)
   576  (BNEZ (SLT x y) yes no) => (BLT x y yes no)
   577  (BEQZ (SLTU x y) yes no) => (BGEU x y yes no)
   578  (BNEZ (SLTU x y) yes no) => (BLTU x y yes no)
   579  (BEQZ (SLTI [x] y) yes no) => (BGE y (MOVDconst [x]) yes no)
   580  (BNEZ (SLTI [x] y) yes no) => (BLT y (MOVDconst [x]) yes no)
   581  (BEQZ (SLTIU [x] y) yes no) => (BGEU y (MOVDconst [x]) yes no)
   582  (BNEZ (SLTIU [x] y) yes no) => (BLTU y (MOVDconst [x]) yes no)
   583  
   584  // Convert branch with zero to more optimal branch zero.
   585  (BEQ (MOVDconst [0]) cond yes no) => (BEQZ cond yes no)
   586  (BEQ cond (MOVDconst [0]) yes no) => (BEQZ cond yes no)
   587  (BNE (MOVDconst [0]) cond yes no) => (BNEZ cond yes no)
   588  (BNE cond (MOVDconst [0]) yes no) => (BNEZ cond yes no)
   589  (BLT (MOVDconst [0]) cond yes no) => (BGTZ cond yes no)
   590  (BLT cond (MOVDconst [0]) yes no) => (BLTZ cond yes no)
   591  (BGE (MOVDconst [0]) cond yes no) => (BLEZ cond yes no)
   592  (BGE cond (MOVDconst [0]) yes no) => (BGEZ cond yes no)
   593  
   594  // Remove redundant NEG from SEQZ/SNEZ.
   595  (SEQZ (NEG x)) => (SEQZ x)
   596  (SNEZ (NEG x)) => (SNEZ x)
   597  
   598  // Remove redundant SEQZ/SNEZ.
   599  (SEQZ (SEQZ x)) => (SNEZ x)
   600  (SEQZ (SNEZ x)) => (SEQZ x)
   601  (SNEZ (SEQZ x)) => (SEQZ x)
   602  (SNEZ (SNEZ x)) => (SNEZ x)
   603  
   604  // Store zero.
   605  (MOVBstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVBstorezero [off] {sym} ptr mem)
   606  (MOVHstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVHstorezero [off] {sym} ptr mem)
   607  (MOVWstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVWstorezero [off] {sym} ptr mem)
   608  (MOVDstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVDstorezero [off] {sym} ptr mem)
   609  
   610  // Boolean ops are already extended.
   611  (MOVBUreg x:((FLES|FLTS|FEQS|FNES) _ _)) => x
   612  (MOVBUreg x:((FLED|FLTD|FEQD|FNED) _ _)) => x
   613  (MOVBUreg x:((SEQZ|SNEZ) _)) => x
   614  (MOVBUreg x:((SLT|SLTU) _ _)) => x
   615  
   616  // Avoid extending when already sufficiently masked.
   617  (MOVBreg  x:(ANDI [c] y)) && c >= 0 && int64(int8(c)) == c => x
   618  (MOVHreg  x:(ANDI [c] y)) && c >= 0 && int64(int16(c)) == c => x
   619  (MOVWreg  x:(ANDI [c] y)) && c >= 0 && int64(int32(c)) == c => x
   620  (MOVBUreg x:(ANDI [c] y)) && c >= 0 && int64(uint8(c)) == c => x
   621  (MOVHUreg x:(ANDI [c] y)) && c >= 0 && int64(uint16(c)) == c => x
   622  (MOVWUreg x:(ANDI [c] y)) && c >= 0 && int64(uint32(c)) == c => x
   623  
   624  // Combine masking and zero extension.
   625  (MOVBUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint8(c))] x)
   626  (MOVHUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint16(c))] x)
   627  (MOVWUreg (ANDI [c] x)) && c < 0 => (AND (MOVDconst [int64(uint32(c))]) x)
   628  
   629  // Avoid sign/zero extension for consts.
   630  (MOVBreg  (MOVDconst [c])) => (MOVDconst [int64(int8(c))])
   631  (MOVHreg  (MOVDconst [c])) => (MOVDconst [int64(int16(c))])
   632  (MOVWreg  (MOVDconst [c])) => (MOVDconst [int64(int32(c))])
   633  (MOVBUreg (MOVDconst [c])) => (MOVDconst [int64(uint8(c))])
   634  (MOVHUreg (MOVDconst [c])) => (MOVDconst [int64(uint16(c))])
   635  (MOVWUreg (MOVDconst [c])) => (MOVDconst [int64(uint32(c))])
   636  
   637  // Avoid sign/zero extension after properly typed load.
   638  (MOVBreg  x:(MOVBload  _ _)) => (MOVDreg x)
   639  (MOVHreg  x:(MOVBload  _ _)) => (MOVDreg x)
   640  (MOVHreg  x:(MOVBUload _ _)) => (MOVDreg x)
   641  (MOVHreg  x:(MOVHload  _ _)) => (MOVDreg x)
   642  (MOVWreg  x:(MOVBload  _ _)) => (MOVDreg x)
   643  (MOVWreg  x:(MOVBUload _ _)) => (MOVDreg x)
   644  (MOVWreg  x:(MOVHload  _ _)) => (MOVDreg x)
   645  (MOVWreg  x:(MOVHUload _ _)) => (MOVDreg x)
   646  (MOVWreg  x:(MOVWload  _ _)) => (MOVDreg x)
   647  (MOVBUreg x:(MOVBUload _ _)) => (MOVDreg x)
   648  (MOVHUreg x:(MOVBUload _ _)) => (MOVDreg x)
   649  (MOVHUreg x:(MOVHUload _ _)) => (MOVDreg x)
   650  (MOVWUreg x:(MOVBUload _ _)) => (MOVDreg x)
   651  (MOVWUreg x:(MOVHUload _ _)) => (MOVDreg x)
   652  (MOVWUreg x:(MOVWUload _ _)) => (MOVDreg x)
   653  
   654  // Avoid zero extension after properly typed atomic operation.
   655  (MOVBUreg x:(Select0 (LoweredAtomicLoad8 _ _))) => (MOVDreg x)
   656  (MOVBUreg x:(Select0 (LoweredAtomicCas32 _ _ _ _))) => (MOVDreg x)
   657  (MOVBUreg x:(Select0 (LoweredAtomicCas64 _ _ _ _))) => (MOVDreg x)
   658  
   659  // Avoid sign extension after word arithmetic.
   660  (MOVWreg x:(ADDIW   _)) => (MOVDreg x)
   661  (MOVWreg x:(SUBW  _ _)) => (MOVDreg x)
   662  (MOVWreg x:(NEGW    _)) => (MOVDreg x)
   663  (MOVWreg x:(MULW  _ _)) => (MOVDreg x)
   664  (MOVWreg x:(DIVW  _ _)) => (MOVDreg x)
   665  (MOVWreg x:(DIVUW _ _)) => (MOVDreg x)
   666  (MOVWreg x:(REMW  _ _)) => (MOVDreg x)
   667  (MOVWreg x:(REMUW _ _)) => (MOVDreg x)
   668  (MOVWreg x:(ROLW  _ _)) => (MOVDreg x)
   669  (MOVWreg x:(RORW  _ _)) => (MOVDreg x)
   670  (MOVWreg x:(RORIW   _)) => (MOVDreg x)
   671  
   672  // Fold double extensions.
   673  (MOVBreg  x:(MOVBreg  _)) => (MOVDreg x)
   674  (MOVHreg  x:(MOVBreg  _)) => (MOVDreg x)
   675  (MOVHreg  x:(MOVBUreg _)) => (MOVDreg x)
   676  (MOVHreg  x:(MOVHreg  _)) => (MOVDreg x)
   677  (MOVWreg  x:(MOVBreg  _)) => (MOVDreg x)
   678  (MOVWreg  x:(MOVBUreg _)) => (MOVDreg x)
   679  (MOVWreg  x:(MOVHreg  _)) => (MOVDreg x)
   680  (MOVWreg  x:(MOVWreg  _)) => (MOVDreg x)
   681  (MOVBUreg x:(MOVBUreg _)) => (MOVDreg x)
   682  (MOVHUreg x:(MOVBUreg _)) => (MOVDreg x)
   683  (MOVHUreg x:(MOVHUreg _)) => (MOVDreg x)
   684  (MOVWUreg x:(MOVBUreg _)) => (MOVDreg x)
   685  (MOVWUreg x:(MOVHUreg _)) => (MOVDreg x)
   686  (MOVWUreg x:(MOVWUreg _)) => (MOVDreg x)
   687  
   688  // Do not extend before store.
   689  (MOVBstore [off] {sym} ptr (MOVBreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   690  (MOVBstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   691  (MOVBstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   692  (MOVBstore [off] {sym} ptr (MOVBUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   693  (MOVBstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   694  (MOVBstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   695  (MOVHstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   696  (MOVHstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   697  (MOVHstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   698  (MOVHstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   699  (MOVWstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVWstore [off] {sym} ptr x mem)
   700  (MOVWstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVWstore [off] {sym} ptr x mem)
   701  
   702  // Replace extend after load with alternate load where possible.
   703  (MOVBreg  <t> x:(MOVBUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBload  <t> [off] {sym} ptr mem)
   704  (MOVHreg  <t> x:(MOVHUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHload  <t> [off] {sym} ptr mem)
   705  (MOVWreg  <t> x:(MOVWUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWload  <t> [off] {sym} ptr mem)
   706  (MOVBUreg <t> x:(MOVBload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBUload <t> [off] {sym} ptr mem)
   707  (MOVHUreg <t> x:(MOVHload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHUload <t> [off] {sym} ptr mem)
   708  (MOVWUreg <t> x:(MOVWload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWUload <t> [off] {sym} ptr mem)
   709  
   710  // If a register move has only 1 use, just use the same register without emitting instruction
   711  // MOVnop does not emit an instruction, only for ensuring the type.
   712  (MOVDreg x) && x.Uses == 1 => (MOVDnop x)
   713  
   714  // TODO: we should be able to get rid of MOVDnop all together.
   715  // But for now, this is enough to get rid of lots of them.
   716  (MOVDnop (MOVDconst [c])) => (MOVDconst [c])
   717  
   718  // Avoid unnecessary zero and sign extension when right shifting.
   719  (SRAI <t> [x] (MOVWreg  y)) && x >= 0 && x <= 31 => (SRAIW <t> [int64(x)] y)
   720  (SRLI <t> [x] (MOVWUreg y)) && x >= 0 && x <= 31 => (SRLIW <t> [int64(x)] y)
   721  
   722  // Replace right shifts that exceed size of signed type.
   723  (SRAI <t> [x] (MOVBreg y)) && x >=  8 => (SRAI  [63] (SLLI <t> [56] y))
   724  (SRAI <t> [x] (MOVHreg y)) && x >= 16 => (SRAI  [63] (SLLI <t> [48] y))
   725  (SRAI <t> [x] (MOVWreg y)) && x >= 32 => (SRAIW [31] y)
   726  
   727  // Eliminate right shifts that exceed size of unsigned type.
   728  (SRLI <t> [x] (MOVBUreg y)) && x >=  8 => (MOVDconst <t> [0])
   729  (SRLI <t> [x] (MOVHUreg y)) && x >= 16 => (MOVDconst <t> [0])
   730  (SRLI <t> [x] (MOVWUreg y)) && x >= 32 => (MOVDconst <t> [0])
   731  
   732  // Fold constant into immediate instructions where possible.
   733  (ADD (MOVDconst <t> [val]) x) && is32Bit(val) && !t.IsPtr() => (ADDI [val] x)
   734  (AND (MOVDconst [val]) x) && is32Bit(val) => (ANDI [val] x)
   735  (OR  (MOVDconst [val]) x) && is32Bit(val) => (ORI  [val] x)
   736  (XOR (MOVDconst [val]) x) && is32Bit(val) => (XORI [val] x)
   737  (ROL  x (MOVDconst [val])) => (RORI  [int64(int8(-val)&63)] x)
   738  (ROLW x (MOVDconst [val])) => (RORIW [int64(int8(-val)&31)] x)
   739  (ROR  x (MOVDconst [val])) => (RORI  [int64(val&63)] x)
   740  (RORW x (MOVDconst [val])) => (RORIW [int64(val&31)] x)
   741  (SLL  x (MOVDconst [val])) => (SLLI [int64(val&63)] x)
   742  (SRL  x (MOVDconst [val])) => (SRLI [int64(val&63)] x)
   743  (SLLW x (MOVDconst [val])) => (SLLIW [int64(val&31)] x)
   744  (SRLW x (MOVDconst [val])) => (SRLIW [int64(val&31)] x)
   745  (SRA  x (MOVDconst [val])) => (SRAI [int64(val&63)] x)
   746  (SRAW x (MOVDconst [val])) => (SRAIW [int64(val&31)] x)
   747  (SLT  x (MOVDconst [val])) && val >= -2048 && val <= 2047 => (SLTI  [val] x)
   748  (SLTU x (MOVDconst [val])) && val >= -2048 && val <= 2047 => (SLTIU [val] x)
   749  
   750  // Replace negated left rotation with right rotation.
   751  (ROL  x (NEG y)) => (ROR  x y)
   752  (ROLW x (NEG y)) => (RORW x y)
   753  
   754  // Convert const subtraction into ADDI with negative immediate, where possible.
   755  (SUB x (MOVDconst [val])) && is32Bit(-val) => (ADDI [-val] x)
   756  (SUB <t> (MOVDconst [val]) y) && is32Bit(-val) => (NEG (ADDI <t> [-val] y))
   757  
   758  // Subtraction of zero.
   759  (SUB  x (MOVDconst [0])) => x
   760  (SUBW x (MOVDconst [0])) => (ADDIW [0] x)
   761  
   762  // Subtraction from zero.
   763  (SUB  (MOVDconst [0]) x) => (NEG x)
   764  (SUBW (MOVDconst [0]) x) => (NEGW x)
   765  
   766  // Fold negation into subtraction.
   767  (NEG (SUB x y)) => (SUB y x)
   768  (NEG <t> s:(ADDI [val] (SUB x y))) && s.Uses == 1 && is32Bit(-val) => (ADDI [-val] (SUB <t> y x))
   769  
   770  // Double negation.
   771  (NEG (NEG x)) => x
   772  
   773  // Addition of zero or two constants.
   774  (ADDI [0] x) => x
   775  (ADDI [x] (MOVDconst [y])) && is32Bit(x + y) => (MOVDconst [x + y])
   776  
   777  // ANDI with all zeros, all ones or two constants.
   778  (ANDI [0]  x) => (MOVDconst [0])
   779  (ANDI [-1] x) => x
   780  (ANDI [x] (MOVDconst [y])) => (MOVDconst [x & y])
   781  
   782  // ORI with all zeroes, all ones or two constants.
   783  (ORI [0]  x) => x
   784  (ORI [-1] x) => (MOVDconst [-1])
   785  (ORI [x] (MOVDconst [y])) => (MOVDconst [x | y])
   786  
   787  // Combine operations with immediate.
   788  (ADDI [x] (ADDI [y] z)) && is32Bit(x + y) => (ADDI [x + y] z)
   789  (ANDI [x] (ANDI [y] z)) => (ANDI [x & y] z)
   790  (ORI  [x] (ORI  [y] z)) => (ORI  [x | y] z)
   791  
   792  // Negation of a constant.
   793  (NEG  (MOVDconst [x])) => (MOVDconst [-x])
   794  (NEGW (MOVDconst [x])) => (MOVDconst [int64(int32(-x))])
   795  
   796  // Shift of a constant.
   797  (SLLI [x] (MOVDconst [y])) && is32Bit(y << uint32(x)) => (MOVDconst [y << uint32(x)])
   798  (SRLI [x] (MOVDconst [y])) => (MOVDconst [int64(uint64(y) >> uint32(x))])
   799  (SRAI [x] (MOVDconst [y])) => (MOVDconst [int64(y) >> uint32(x)])
   800  
   801  // SLTI/SLTIU with constants.
   802  (SLTI  [x] (MOVDconst [y])) => (MOVDconst [b2i(int64(y) < int64(x))])
   803  (SLTIU [x] (MOVDconst [y])) => (MOVDconst [b2i(uint64(y) < uint64(x))])
   804  
   805  // SLTI/SLTIU with known outcomes.
   806  (SLTI  [x] (ANDI [y] _)) && y >= 0 && int64(y) < int64(x) => (MOVDconst [1])
   807  (SLTIU [x] (ANDI [y] _)) && y >= 0 && uint64(y) < uint64(x) => (MOVDconst [1])
   808  (SLTI  [x] (ORI  [y] _)) && y >= 0 && int64(y) >= int64(x) => (MOVDconst [0])
   809  (SLTIU [x] (ORI  [y] _)) && y >= 0 && uint64(y) >= uint64(x) => (MOVDconst [0])
   810  
   811  // SLT/SLTU with known outcomes.
   812  (SLT  x x) => (MOVDconst [0])
   813  (SLTU x x) => (MOVDconst [0])
   814  
   815  // Deadcode for LoweredMuluhilo
   816  (Select0 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MULHU x y)
   817  (Select1 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MUL x y)
   818  
   819  (FADD(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FMADD(S|D) x y a)
   820  (FSUB(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FNMSUB(S|D) x y a)
   821  (FSUB(S|D) (FMUL(S|D) x y) a) && a.Block.Func.useFMA(v) => (FMSUB(S|D) x y a)
   822  
   823  // Merge negation into fused multiply-add and multiply-subtract.
   824  //
   825  // Key:
   826  //
   827  //   [+ -](x * y [+ -] z).
   828  //    _ N         A S
   829  //                D U
   830  //                D B
   831  //
   832  // Note: multiplication commutativity handled by rule generator.
   833  (F(MADD|NMADD|MSUB|NMSUB)S neg:(FNEGS x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)S x y z)
   834  (F(MADD|NMADD|MSUB|NMSUB)S x y neg:(FNEGS z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)S x y z)
   835  (F(MADD|NMADD|MSUB|NMSUB)D neg:(FNEGD x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)D x y z)
   836  (F(MADD|NMADD|MSUB|NMSUB)D x y neg:(FNEGD z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)D x y z)
   837  

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