Commit 6a4ed8e3 authored Feb 12, 2015 by Hans Wennborg

Merging r228979:

------------------------------------------------------------------------
r228979 | majnemer | 2015-02-12 15:26:26 -0800 (Thu, 12 Feb 2015) | 8 lines

X86: Don't crash if we can't decode the pshufb mask

Constant pool entries are uniqued by their contents regardless of their
type.  This means that a pshufb can have a shuffle mask which isn't a
simple array of bytes.

The code path which attempts to decode the mask didn't check for
failure, causing PR22559.
------------------------------------------------------------------------

llvm-svn: 228983

parent 2f356a13

llvm/lib/Target/X86/X86ISelLowering.cpp

+2 −0

Original line number	Diff line number	Diff line
		@@ -5473,6 +5473,8 @@ static bool getTargetShuffleMask(SDNode *N, MVT VT,

		if (auto *C = dyn_cast<Constant>(MaskCP->getConstVal())) {
		DecodePSHUFBMask(C, Mask);
		if (Mask.empty())
		return false;
		break;
		}

llvm/test/CodeGen/X86/pshufb-mask-comments.ll

+12 −0

Original line number	Diff line number	Diff line
		@@ -37,4 +37,16 @@ define <16 x i8> @test4(<2 x i64>* %V) {
		ret <16 x i8> %1
		}

		define <16 x i8> @test5() {
		; CHECK-LABEL: test5
		; CHECK: pshufb {{.*}}
		store <2 x i64> <i64 1, i64 0>, <2 x i64>* undef, align 16
		%l = load <2 x i64>* undef, align 16
		%shuffle = shufflevector <2 x i64> %l, <2 x i64> undef, <2 x i32> zeroinitializer
		store <2 x i64> %shuffle, <2 x i64>* undef, align 16
		%1 = load <16 x i8>* undef, align 16
		%2 = call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> undef, <16 x i8> %1)
		ret <16 x i8> %2
		}

		declare <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8>, <16 x i8>) nounwind readnone