From 331297c62e028190c8e7c4053d9a7d434875c3e6 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Tue, 28 Mar 2017 23:20:37 +0000 Subject: [PATCH] [AVX-512] Punt on fast-isel of truncates to i1 when AVX512 is enabled. We should be masking the value and emitting a register copy like we do in non-fast isel. Instead we were just updating the value map and emitting nothing. After r298928 we started seeing cases where we would create a copy from GR8 to GR32 because the source register in a VK1 to GR32 copy was replaced by the GR8 going into a truncate. This fixes PR32451. llvm-svn: 298957 --- llvm/lib/Target/X86/X86FastISel.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp index 7d38abb..be1efa6 100644 --- a/llvm/lib/Target/X86/X86FastISel.cpp +++ b/llvm/lib/Target/X86/X86FastISel.cpp @@ -2512,7 +2512,8 @@ bool X86FastISel::X86SelectTrunc(const Instruction *I) { EVT DstVT = TLI.getValueType(DL, I->getType()); // This code only handles truncation to byte. - if (DstVT != MVT::i8 && DstVT != MVT::i1) + // TODO: Support truncate to i1 with AVX512. + if (DstVT != MVT::i8 && (DstVT != MVT::i1 || Subtarget->hasAVX512())) return false; if (!TLI.isTypeLegal(SrcVT)) return false; -- 2.7.4