From 85b904d875ca98408b27f773859b15c0aba1bf75 Mon Sep 17 00:00:00 2001 From: Quentin Colombet Date: Thu, 27 Mar 2014 22:27:41 +0000 Subject: [PATCH] [X86][Vector Cost Model] Add a comment to explain the workaround in my previous commit (r204884). llvm-svn: 204972 --- llvm/lib/Target/X86/X86TargetTransformInfo.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp index 2d44db0acdbc..f58c94683fdc 100644 --- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp +++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp @@ -512,6 +512,11 @@ unsigned X86TTI::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const { { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i8, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i16, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i32, 6 }, + // The generic code to compute the scalar overhead is currently broken. + // Workaround this limitation by estimating the scalarization overhead + // here. We have roughly 10 instructions per scalar element. + // Multiply that by the vector width. + // FIXME: remove that when PR19268 is fixed. { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i64, 2*10 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i64, 4*10 }, -- 2.34.1