diff options
Diffstat (limited to 'lib/Target/X86/X86InstrShiftRotate.td')
| -rw-r--r-- | lib/Target/X86/X86InstrShiftRotate.td | 84 |
1 files changed, 83 insertions, 1 deletions
diff --git a/lib/Target/X86/X86InstrShiftRotate.td b/lib/Target/X86/X86InstrShiftRotate.td index bdeb63f..1185941 100644 --- a/lib/Target/X86/X86InstrShiftRotate.td +++ b/lib/Target/X86/X86InstrShiftRotate.td @@ -51,6 +51,7 @@ def SHL64ri : RIi8<0xC1, MRM4r, (outs GR64:$dst), // NOTE: We don't include patterns for shifts of a register by one, because // 'add reg,reg' is cheaper (and we have a Pat pattern for shift-by-one). +let hasSideEffects = 0 in { def SHL8r1 : I<0xD0, MRM4r, (outs GR8:$dst), (ins GR8:$src1), "shl{b}\t$dst", [], IIC_SR>; def SHL16r1 : I<0xD1, MRM4r, (outs GR16:$dst), (ins GR16:$src1), @@ -59,8 +60,9 @@ def SHL32r1 : I<0xD1, MRM4r, (outs GR32:$dst), (ins GR32:$src1), "shl{l}\t$dst", [], IIC_SR>; def SHL64r1 : RI<0xD1, MRM4r, (outs GR64:$dst), (ins GR64:$src1), "shl{q}\t$dst", [], IIC_SR>; +} // hasSideEffects = 0 } // isConvertibleToThreeAddress = 1 -} // Constraints = "$src = $dst" +} // Constraints = "$src = $dst" // FIXME: Why do we need an explicit "Uses = [CL]" when the instr has a pattern @@ -333,6 +335,7 @@ def SAR64m1 : RI<0xD1, MRM7m, (outs), (ins i64mem:$dst), // Rotate instructions //===----------------------------------------------------------------------===// +let hasSideEffects = 0 in { let Constraints = "$src1 = $dst" in { def RCL8r1 : I<0xD0, MRM2r, (outs GR8:$dst), (ins GR8:$src1), "rcl{b}\t$dst", [], IIC_SR>; @@ -455,6 +458,7 @@ def RCR32mCL : I<0xD3, MRM3m, (outs), (ins i32mem:$dst), def RCR64mCL : RI<0xD3, MRM3m, (outs), (ins i64mem:$dst), "rcr{q}\t{%cl, $dst|$dst, CL}", [], IIC_SR>; } +} // hasSideEffects = 0 let Constraints = "$src1 = $dst" in { // FIXME: provide shorter instructions when imm8 == 1 @@ -839,6 +843,16 @@ def SHRD64mri8 : RIi8<0xAC, MRMDestMem, } // Defs = [EFLAGS] +def ROT32L2R_imm8 : SDNodeXForm<imm, [{ + // Convert a ROTL shamt to a ROTR shamt on 32-bit integer. + return getI8Imm(32 - N->getZExtValue()); +}]>; + +def ROT64L2R_imm8 : SDNodeXForm<imm, [{ + // Convert a ROTL shamt to a ROTR shamt on 64-bit integer. + return getI8Imm(64 - N->getZExtValue()); +}]>; + multiclass bmi_rotate<string asm, RegisterClass RC, X86MemOperand x86memop> { let neverHasSideEffects = 1 in { def ri : Ii8<0xF0, MRMSrcReg, (outs RC:$dst), (ins RC:$src1, i8imm:$src2), @@ -873,4 +887,72 @@ let Predicates = [HasBMI2] in { defm SHRX64 : bmi_shift<"shrx{q}", GR64, i64mem>, T8XD, VEX_W; defm SHLX32 : bmi_shift<"shlx{l}", GR32, i32mem>, T8, OpSize; defm SHLX64 : bmi_shift<"shlx{q}", GR64, i64mem>, T8, OpSize, VEX_W; + + // Prefer RORX which is non-destructive and doesn't update EFLAGS. + let AddedComplexity = 10 in { + def : Pat<(rotl GR32:$src, (i8 imm:$shamt)), + (RORX32ri GR32:$src, (ROT32L2R_imm8 imm:$shamt))>; + def : Pat<(rotl GR64:$src, (i8 imm:$shamt)), + (RORX64ri GR64:$src, (ROT64L2R_imm8 imm:$shamt))>; + } + + def : Pat<(rotl (loadi32 addr:$src), (i8 imm:$shamt)), + (RORX32mi addr:$src, (ROT32L2R_imm8 imm:$shamt))>; + def : Pat<(rotl (loadi64 addr:$src), (i8 imm:$shamt)), + (RORX64mi addr:$src, (ROT64L2R_imm8 imm:$shamt))>; + + // Prefer SARX/SHRX/SHLX over SAR/SHR/SHL with variable shift BUT not + // immedidate shift, i.e. the following code is considered better + // + // mov %edi, %esi + // shl $imm, %esi + // ... %edi, ... + // + // than + // + // movb $imm, %sil + // shlx %sil, %edi, %esi + // ... %edi, ... + // + let AddedComplexity = 1 in { + def : Pat<(sra GR32:$src1, GR8:$src2), + (SARX32rr GR32:$src1, + (INSERT_SUBREG + (i32 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + def : Pat<(sra GR64:$src1, GR8:$src2), + (SARX64rr GR64:$src1, + (INSERT_SUBREG + (i64 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + + def : Pat<(srl GR32:$src1, GR8:$src2), + (SHRX32rr GR32:$src1, + (INSERT_SUBREG + (i32 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + def : Pat<(srl GR64:$src1, GR8:$src2), + (SHRX64rr GR64:$src1, + (INSERT_SUBREG + (i64 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + + def : Pat<(shl GR32:$src1, GR8:$src2), + (SHLX32rr GR32:$src1, + (INSERT_SUBREG + (i32 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + def : Pat<(shl GR64:$src1, GR8:$src2), + (SHLX64rr GR64:$src1, + (INSERT_SUBREG + (i64 (IMPLICIT_DEF)), GR8:$src2, sub_8bit))>; + } + + // Patterns on SARXrm/SHRXrm/SHLXrm are explicitly omitted to favor + // + // mov (%ecx), %esi + // shl $imm, $esi + // + // over + // + // movb $imm %al + // shlx %al, (%ecx), %esi + // + // As SARXrr/SHRXrr/SHLXrr is favored on variable shift, the peephole + // optimization will fold them into SARXrm/SHRXrm/SHLXrm if possible. } |