From: Sanjay Patel Date: Wed, 3 Apr 2019 22:40:35 +0000 (+0000) Subject: [x86] fold shuffles of h-ops that have an undef operand X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=92604432b4a99401c51ccaf2fc1c4e9c0e120637;p=llvm [x86] fold shuffles of h-ops that have an undef operand If an operand is undef, we can assume it's the same as the other operand. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357644 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 84009979ea1..a05fd557ca2 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -32880,8 +32880,8 @@ static SDValue foldShuffleOfHorizOp(SDNode *N) { // lanes of each operand as: // v4X32: A[0] + A[1] , A[2] + A[3] , B[0] + B[1] , B[2] + B[3] // ...similarly for v2f64 and v8i16. - // TODO: Handle UNDEF operands. - if (HOp.getOperand(0) != HOp.getOperand(1)) + if (!HOp.getOperand(0).isUndef() && !HOp.getOperand(1).isUndef() && + HOp.getOperand(0) != HOp.getOperand(1)) return SDValue(); // When the operands of a horizontal math op are identical, the low half of diff --git a/test/CodeGen/X86/haddsub-shuf.ll b/test/CodeGen/X86/haddsub-shuf.ll index e50d6af6e09..c37e9862ed7 100644 --- a/test/CodeGen/X86/haddsub-shuf.ll +++ b/test/CodeGen/X86/haddsub-shuf.ll @@ -381,7 +381,6 @@ define <4 x double> @hadd_v4f64_scalar_splat(<4 x double> %a) { ; AVX-LABEL: hadd_v4f64_scalar_splat: ; AVX: # %bb.0: ; AVX-NEXT: vhaddpd %ymm0, %ymm0, %ymm0 -; AVX-NEXT: vmovddup {{.*#+}} ymm0 = ymm0[0,0,2,2] ; AVX-NEXT: retq %a0 = extractelement <4 x double> %a, i32 0 %a1 = extractelement <4 x double> %a, i32 1