llvm-6502/test/CodeGen/X86/neg_fp.ll

; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse41 -o %t -f
; RUN: grep xorps %t | count 1

; Test that when we don't -enable-unsafe-fp-math, we don't do the optimization
; -0 - (A - B) to (B - A) because A==B, -0 != 0

define float @negfp(float %a, float %b) {
entry:
	%sub = fsub float %a, %b		; <float> [#uses=1]
	%neg = fsub float -0.000000e+00, %sub		; <float> [#uses=1]
	ret float %neg
}
If unsafe FP optimization is not set, don't allow -(A-B) => B-A because when A==B, -0.0 != +0.0. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63474 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-31 06:07:45 +00:00			`; RUN: llvm-as < %s \| llc -march=x86 -mattr=+sse41 -o %t -f`
			`; RUN: grep xorps %t \| count 1`

			`; Test that when we don't -enable-unsafe-fp-math, we don't do the optimization`
			`; -0 - (A - B) to (B - A) because A==B, -0 != 0`

			`define float @negfp(float %a, float %b) {`
			`entry:`
Split the Add, Sub, and Mul instruction opcodes into separate integer and floating-point opcodes, introducing FAdd, FSub, and FMul. For now, the AsmParser, BitcodeReader, and IRBuilder all preserve backwards compatability, and the Core LLVM APIs preserve backwards compatibility for IR producers. Most front-ends won't need to change immediately. This implements the first step of the plan outlined here: http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72897 91177308-0d34-0410-b5e6-96231b3b80d8 2009-06-04 22:49:04 +00:00			`%sub = fsub float %a, %b ; <float> [#uses=1]`
			`%neg = fsub float -0.000000e+00, %sub ; <float> [#uses=1]`
If unsafe FP optimization is not set, don't allow -(A-B) => B-A because when A==B, -0.0 != +0.0. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63474 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-31 06:07:45 +00:00			`ret float %neg`
			`}`