[llvm] r207577 - Two fixes to the vpermilvar optimization.
Rafael Espindola
rafael.espindola at gmail.com
Tue Apr 29 13:41:54 PDT 2014
Author: rafael
Date: Tue Apr 29 15:41:54 2014
New Revision: 207577
URL: http://llvm.org/viewvc/llvm-project?rev=207577&view=rev
Log:
Two fixes to the vpermilvar optimization.
The instcomine logic to handle vpermilvar's pd and 256 variants was incorrect.
The _256 variants have indexes into the individual 128 bit lanes and in all
cases it also has to mask out unused bits.
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
llvm/trunk/test/Transforms/InstCombine/vec_demanded_elts.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=207577&r1=207576&r2=207577&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Tue Apr 29 15:41:54 2014
@@ -725,9 +725,32 @@ Instruction *InstCombiner::visitCallInst
// Convert vpermil* to shufflevector if the mask is constant.
Value *V = II->getArgOperand(1);
if (auto C = dyn_cast<ConstantDataVector>(V)) {
+ unsigned Size = C->getNumElements();
+ assert(Size == 8 || Size == 4 || Size == 2);
+ uint32_t Indexes[8];
+
+ // The intrinsics only read one or two bits, clear the rest.
+ for (unsigned I = 0; I < Size; ++I) {
+ uint32_t Index = C->getElementAsInteger(I) & 0x3;
+ if (II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd ||
+ II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256)
+ Index >>= 1;
+ Indexes[I] = Index;
+ }
+
+ // The _256 variants are a bit trickier since the mask bits always index
+ // into the corresponding 128 half. In order to convert to a generic
+ // shuffle, we have to make that explicit.
+ if (II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_ps_256 ||
+ II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256) {
+ for (unsigned I = Size / 2; I < Size; ++I)
+ Indexes[I] += Size / 2;
+ }
+ auto NewC =
+ ConstantDataVector::get(C->getContext(), makeArrayRef(Indexes, Size));
auto V1 = II->getArgOperand(0);
auto V2 = UndefValue::get(V1->getType());
- auto Shuffle = Builder->CreateShuffleVector(V1, V2, C);
+ auto Shuffle = Builder->CreateShuffleVector(V1, V2, NewC);
return ReplaceInstUsesWith(CI, Shuffle);
}
break;
Modified: llvm/trunk/test/Transforms/InstCombine/vec_demanded_elts.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec_demanded_elts.ll?rev=207577&r1=207576&r2=207577&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_demanded_elts.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec_demanded_elts.ll Tue Apr 29 15:41:54 2014
@@ -318,7 +318,7 @@ define <4 x float> @test_vpermilvar_ps(<
declare <8 x float> @llvm.x86.avx.vpermilvar.ps.256(<8 x float>, <8 x i32>)
define <8 x float> @test_vpermilvar_ps_256(<8 x float> %v) {
; CHECK-LABEL: @test_vpermilvar_ps_256(
-; CHECK: shufflevector <8 x float> %v, <8 x float> undef, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
+; CHECK: shufflevector <8 x float> %v, <8 x float> undef, <8 x i32> <i32 3, i32 2, i32 1, i32 0, i32 7, i32 6, i32 5, i32 4>
%a = tail call <8 x float> @llvm.x86.avx.vpermilvar.ps.256(<8 x float> %v, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>)
ret <8 x float> %a
}
@@ -327,15 +327,15 @@ declare <2 x double> @llvm.x86.avx.vperm
define <2 x double> @test_vpermilvar_pd(<2 x double> %v) {
; CHECK-LABEL: @test_vpermilvar_pd(
; CHECK: shufflevector <2 x double> %v, <2 x double> undef, <2 x i32> <i32 1, i32 0>
- %a = tail call <2 x double> @llvm.x86.avx.vpermilvar.pd(<2 x double> %v, <2 x i32> <i32 1, i32 0>)
+ %a = tail call <2 x double> @llvm.x86.avx.vpermilvar.pd(<2 x double> %v, <2 x i32> <i32 2, i32 0>)
ret <2 x double> %a
}
declare <4 x double> @llvm.x86.avx.vpermilvar.pd.256(<4 x double>, <4 x i32>)
define <4 x double> @test_vpermilvar_pd_256(<4 x double> %v) {
; CHECK-LABEL: @test_vpermilvar_pd_256(
-; CHECK: shufflevector <4 x double> %v, <4 x double> undef, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
- %a = tail call <4 x double> @llvm.x86.avx.vpermilvar.pd.256(<4 x double> %v, <4 x i32> <i32 3, i32 2, i32 1, i32 0>)
+; CHECK: shufflevector <4 x double> %v, <4 x double> undef, <4 x i32> <i32 1, i32 0, i32 3, i32 2>
+ %a = tail call <4 x double> @llvm.x86.avx.vpermilvar.pd.256(<4 x double> %v, <4 x i32> <i32 3, i32 1, i32 2, i32 0>)
ret <4 x double> %a
}
More information about the llvm-commits
mailing list