From: Evan Cheng Date: Mon, 19 Jan 2009 08:08:22 +0000 (+0000) Subject: Now not UINT_TO_FP is legal (it's marked custom), dag combiner won't X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a06ec9efe122b296056961e3914823b07e67b387;p=oota-llvm.git Now not UINT_TO_FP is legal (it's marked custom), dag combiner won't optimize it to a SINT_TO_FP when the sign bit is known zero. X86 isel should perform the optimization itself. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62504 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 544b71cf8f8..0f5103b5c67 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -4884,8 +4884,15 @@ SDValue X86TargetLowering::LowerUINT_TO_FP_i32(SDValue Op, SelectionDAG &DAG) { } SDValue X86TargetLowering::LowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) { - MVT SrcVT = Op.getOperand(0).getValueType(); + SDValue N0 = Op.getOperand(0); + + // Now not UINT_TO_FP is legal (it's marked custom), dag combiner won't + // optimize it to a SINT_TO_FP when the sign bit is known zero. Perform + // the optimization here. + if (DAG.SignBitIsZero(N0)) + return DAG.getNode(ISD::SINT_TO_FP, Op.getValueType(), N0); + MVT SrcVT = N0.getValueType(); if (SrcVT == MVT::i64) { // We only handle SSE2 f64 target here; caller can handle the rest. if (Op.getValueType() != MVT::f64 || !X86ScalarSSEf64) diff --git a/test/CodeGen/X86/uint_to_fp.ll b/test/CodeGen/X86/uint_to_fp.ll index 3ea7a947b96..148437f3ddb 100644 --- a/test/CodeGen/X86/uint_to_fp.ll +++ b/test/CodeGen/X86/uint_to_fp.ll @@ -1,4 +1,5 @@ ; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | not grep {sub.*esp} +; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | grep cvtsi2ss ; rdar://6034396 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"