mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-01-31 20:51:52 +01:00
62ad0a5cf3
As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc
can produce -0.0 where the original code does not:
#include <stdio.h>
int main(int argc) {
float x;
x = -0.8 * argc;
printf("%f\n", (float)((int)x));
return 0;
}
$ clang -O0 -mavx fp.c ; ./a.out
0.000000
$ clang -O1 -mavx fp.c ; ./a.out
-0.000000
Ideally, we'd use IR/node flags to predicate the transform, but the IR parser
doesn't currently allow fast-math-flags on the cast instructions. So for now,
just use the function attribute that corresponds to clang's "-fno-signed-zeros"
option.
Differential Revision: https://reviews.llvm.org/D48085
llvm-svn: 335761
81 lines
1.7 KiB
LLVM
81 lines
1.7 KiB
LLVM
; RUN: llc -verify-machineinstrs -mcpu=a2 < %s | FileCheck %s
|
|
target datalayout = "E-m:e-i64:64-n32:64"
|
|
target triple = "powerpc64-unknown-linux-gnu"
|
|
|
|
; Function Attrs: nounwind readonly
|
|
define double @test1(i64* nocapture readonly %x) #0 {
|
|
entry:
|
|
%0 = load i64, i64* %x, align 8
|
|
%conv = sitofp i64 %0 to double
|
|
ret double %conv
|
|
|
|
; CHECK-LABEL: @test1
|
|
; CHECK: lfd [[REG1:[0-9]+]], 0(3)
|
|
; CHECK: fcfid 1, [[REG1]]
|
|
; CHECK: blr
|
|
}
|
|
|
|
; Function Attrs: nounwind readonly
|
|
define double @test2(i32* nocapture readonly %x) #0 {
|
|
entry:
|
|
%0 = load i32, i32* %x, align 4
|
|
%conv = sitofp i32 %0 to double
|
|
ret double %conv
|
|
|
|
; CHECK-LABEL: @test2
|
|
; CHECK: lfiwax [[REG1:[0-9]+]], 0, 3
|
|
; CHECK: fcfid 1, [[REG1]]
|
|
; CHECK: blr
|
|
}
|
|
|
|
; Function Attrs: nounwind readnone
|
|
define float @foo(float %X) #0 {
|
|
entry:
|
|
%conv = fptosi float %X to i32
|
|
%conv1 = sitofp i32 %conv to float
|
|
ret float %conv1
|
|
|
|
; CHECK-LABEL: @foo
|
|
; CHECK: friz 1, 1
|
|
; CHECK: blr
|
|
}
|
|
|
|
; Function Attrs: nounwind readnone
|
|
define double @food(double %X) #0 {
|
|
entry:
|
|
%conv = fptosi double %X to i32
|
|
%conv1 = sitofp i32 %conv to double
|
|
ret double %conv1
|
|
|
|
; CHECK-LABEL: @food
|
|
; CHECK: friz 1, 1
|
|
; CHECK: blr
|
|
}
|
|
|
|
; Function Attrs: nounwind readnone
|
|
define float @foou(float %X) #0 {
|
|
entry:
|
|
%conv = fptoui float %X to i32
|
|
%conv1 = uitofp i32 %conv to float
|
|
ret float %conv1
|
|
|
|
; CHECK-LABEL: @foou
|
|
; CHECK: friz 1, 1
|
|
; CHECK: blr
|
|
}
|
|
|
|
; Function Attrs: nounwind readnone
|
|
define double @fooud(double %X) #0 {
|
|
entry:
|
|
%conv = fptoui double %X to i32
|
|
%conv1 = uitofp i32 %conv to double
|
|
ret double %conv1
|
|
|
|
; CHECK-LABEL: @fooud
|
|
; CHECK: friz 1, 1
|
|
; CHECK: blr
|
|
}
|
|
|
|
attributes #0 = { nounwind readonly "no-signed-zeros-fp-math"="true" }
|
|
|