replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[X86] Use min/max to optimze unsigend vector comparison on X86 

Use PMIN/PMAX for UGE/ULE vector comparions to reduce the number of required
instructions. This trick also works for UGT/ULT, but there is no advantage in
doing so. It wouldn't reduce the number of instructions and it would actually
reduce performance.

Reviewer: Ben

radar:5972691

llvm-svn: 186432
This commit is contained in:
Juergen Ributzka 2013-07-16 18:20:45 +00:00
parent 8b77f18da0
commit 3d527d80b8
2 changed files with 148 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
llvm/lib/Target/X86/X86ISelLowering.cpp
View File

@ -9351,8 +9351,8 @@ static SDValue LowerVSETCC(SDValue Op, const X86Subtarget *Subtarget,
// GT and EQ comparisons for integer, swapping operands and multiple
// operations may be required for some comparisons.
unsigned Opc;
bool Swap = false, Invert = false, FlipSigns = false;
bool Swap = false, Invert = false, FlipSigns = false, MinMax = false;
switch (SetCCOpcode) {
default: llvm_unreachable("Unexpected SETCC condition");
case ISD::SETNE: Invert = true;
@ -9366,6 +9366,23 @@ static SDValue LowerVSETCC(SDValue Op, const X86Subtarget *Subtarget,
case ISD::SETUGE: Swap = true;
case ISD::SETULE: Opc = X86ISD::PCMPGT; FlipSigns = true; Invert = true; break;
}
// Special case: Use min/max operations for SETULE/SETUGE
MVT VET = VT.getVectorElementType();
bool hasMinMax =
(Subtarget->hasSSE41() && (VET >= MVT::i8 && VET <= MVT::i32))
|| (Subtarget->hasSSE2() && (VET == MVT::i8));
if (hasMinMax) {
switch (SetCCOpcode) {
default: break;
case ISD::SETULE: Opc = X86ISD::UMIN; MinMax = true; break;
case ISD::SETUGE: Opc = X86ISD::UMAX; MinMax = true; break;
}
if (MinMax) { Swap = false; Invert = false; FlipSigns = false; }
}
if (Swap)
std::swap(Op0, Op1);
@ -9452,6 +9469,9 @@ static SDValue LowerVSETCC(SDValue Op, const X86Subtarget *Subtarget,
// If the logical-not of the result is required, perform that now.
if (Invert)
Result = DAG.getNOT(dl, Result, VT);
if (MinMax)
Result = DAG.getNode(X86ISD::PCMPEQ, dl, VT, Op0, Result);
return Result;
}

126
llvm/test/CodeGen/X86/vec_setcc.ll Normal file
View File

@ -0,0 +1,126 @@
; RUN: llc < %s -mcpu=x86-64 -mattr=sse2 | FileCheck %s -check-prefix=SSE2
; RUN: llc < %s -mcpu=x86-64 -mattr=sse41 | FileCheck %s -check-prefix=SSE41
; RUN: llc < %s -mcpu=x86-64 -mattr=avx | FileCheck %s -check-prefix=AVX
define <16 x i8> @v16i8_icmp_uge(<16 x i8> %a, <16 x i8> %b) nounwind readnone ssp uwtable {
%1 = icmp uge <16 x i8> %a, %b
%2 = sext <16 x i1> %1 to <16 x i8>
ret <16 x i8> %2
; SSE2: _v16i8_icmp_uge:
; SSE2: pmaxub %xmm0, %xmm1
; SSE2: pcmpeqb %xmm1, %xmm0
; SSE41: _v16i8_icmp_uge:
; SSE41: pmaxub %xmm0, %xmm1
; SSE41: pcmpeqb %xmm1, %xmm0
; AVX: _v16i8_icmp_uge:
; AVX: vpmaxub %xmm1, %xmm0, %xmm1
; AVX: vpcmpeqb %xmm1, %xmm0, %xmm0
}
define <16 x i8> @v16i8_icmp_ule(<16 x i8> %a, <16 x i8> %b) nounwind readnone ssp uwtable {
%1 = icmp ule <16 x i8> %a, %b
%2 = sext <16 x i1> %1 to <16 x i8>
ret <16 x i8> %2
; SSE2: _v16i8_icmp_ule:
; SSE2: pminub %xmm0, %xmm1
; SSE2: pcmpeqb %xmm1, %xmm0
; SSE41: _v16i8_icmp_ule:
; SSE41: pminub %xmm0, %xmm1
; SSE41: pcmpeqb %xmm1, %xmm0
; AVX: _v16i8_icmp_ule:
; AVX: vpminub %xmm1, %xmm0, %xmm1
; AVX: vpcmpeqb %xmm1, %xmm0, %xmm0
}
define <8 x i16> @v8i16_icmp_uge(<8 x i16> %a, <8 x i16> %b) nounwind readnone ssp uwtable {
%1 = icmp uge <8 x i16> %a, %b
%2 = sext <8 x i1> %1 to <8 x i16>
ret <8 x i16> %2
; SSE2: _v8i16_icmp_uge:
; SSE2: movdqa LCPI2_0(%rip), %xmm2
; SEE2: pxor %xmm2, %xmm0
; SSE2: pxor %xmm1, %xmm2
; SSE2: pcmpgtw %xmm0, %xmm2
; SSE2: pcmpeqd %xmm0, %xmm0
; SSE2: pxor %xmm2, %xmm0
; SSE41: _v8i16_icmp_uge:
; SSE41: pmaxuw %xmm0, %xmm1
; SSE41: pcmpeqw %xmm1, %xmm0
; AVX: _v8i16_icmp_uge:
; AVX: vpmaxuw %xmm1, %xmm0, %xmm1
; AVX: vpcmpeqw %xmm1, %xmm0, %xmm0
}
define <8 x i16> @v8i16_icmp_ule(<8 x i16> %a, <8 x i16> %b) nounwind readnone ssp uwtable {
%1 = icmp ule <8 x i16> %a, %b
%2 = sext <8 x i1> %1 to <8 x i16>
ret <8 x i16> %2
; SSE2: _v8i16_icmp_ule:
; SSE2: movdqa LCPI3_0(%rip), %xmm2
; SSE2: pxor %xmm2, %xmm1
; SSE2: pxor %xmm2, %xmm0
; SSE2: pcmpgtw %xmm1, %xmm0
; SSE2: pcmpeqd %xmm1, %xmm1
; SSE2: pxor %xmm0, %xmm1
; SSE2: movdqa %xmm1, %xmm0
; SSE41: _v8i16_icmp_ule:
; SSE41: pminuw %xmm0, %xmm1
; SSE41: pcmpeqw %xmm1, %xmm0
; AVX: _v8i16_icmp_ule:
; AVX: vpminuw %xmm1, %xmm0, %xmm1
; AVX: vpcmpeqw %xmm1, %xmm0, %xmm0
}
define <4 x i32> @v4i32_icmp_uge(<4 x i32> %a, <4 x i32> %b) nounwind readnone ssp uwtable {
%1 = icmp uge <4 x i32> %a, %b
%2 = sext <4 x i1> %1 to <4 x i32>
ret <4 x i32> %2
; SSE2: _v4i32_icmp_uge:
; SSE2: movdqa LCPI4_0(%rip), %xmm2
; SSE2: pxor %xmm2, %xmm0
; SSE2: pxor %xmm1, %xmm2
; SSE2: pcmpgtd %xmm0, %xmm2
; SSE2: pcmpeqd %xmm0, %xmm0
; SSE2: pxor %xmm2, %xmm0
; SSE41: _v4i32_icmp_uge:
; SSE41: pmaxud %xmm0, %xmm1
; SSE41: pcmpeqd %xmm1, %xmm0
; AVX: _v4i32_icmp_uge:
; AVX: vpmaxud %xmm1, %xmm0, %xmm1
; AVX: vpcmpeqd %xmm1, %xmm0, %xmm0
}
define <4 x i32> @v4i32_icmp_ule(<4 x i32> %a, <4 x i32> %b) nounwind readnone ssp uwtable {
%1 = icmp ule <4 x i32> %a, %b
%2 = sext <4 x i1> %1 to <4 x i32>
ret <4 x i32> %2
; SSE2: _v4i32_icmp_ule:
; SSE2: movdqa LCPI5_0(%rip), %xmm2
; SSE2: pxor %xmm2, %xmm1
; SSE2: pxor %xmm2, %xmm0
; SSE2: pcmpgtd %xmm1, %xmm0
; SSE2: pcmpeqd %xmm1, %xmm1
; SSE2: pxor %xmm0, %xmm1
; SSE2: movdqa %xmm1, %xmm0
; SSE41: _v4i32_icmp_ule:
; SSE41: pminud %xmm0, %xmm1
; SSE41: pcmpeqd %xmm1, %xmm0
; AVX: _v4i32_icmp_ule:
; AVX: pminud %xmm1, %xmm0, %xmm1
; AVX: pcmpeqd %xmm1, %xmm0, %xmm0
}