llvm-6502/test/CodeGen/X86/fastmath-float-half-conversion.ll
Andrea Di Biagio 770e106ed6 [X86] Teach how to custom lower double-to-half conversions under fast-math.
This patch teaches the backend how to expand a double-half conversion into
a double-float conversion immediately followed by a float-half conversion.
We do this only under fast-math, and if float-half conversions are legal
for the target.

Added test CodeGen/X86/fastmath-float-half-conversion.ll

Differential Revision: http://reviews.llvm.org/D7832


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230276 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 22:59:02 +00:00

53 lines
1.5 KiB
LLVM

; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=+f16c < %s | FileCheck %s --check-prefix=ALL --check-prefix=F16C
; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=+avx < %s | FileCheck %s --check-prefix=ALL --check-prefix=AVX
define zeroext i16 @test1_fast(double %d) #0 {
; ALL-LABEL: test1_fast:
; F16C-NOT: callq {{_+}}truncdfhf2
; F16C: vcvtsd2ss %xmm0, %xmm0, %xmm0
; F16C-NEXT: vcvtps2ph $0, %xmm0, %xmm0
; AVX: callq {{_+}}truncdfhf2
; ALL: ret
entry:
%0 = tail call i16 @llvm.convert.to.fp16.f64(double %d)
ret i16 %0
}
define zeroext i16 @test2_fast(x86_fp80 %d) #0 {
; ALL-LABEL: test2_fast:
; F16C-NOT: callq {{_+}}truncxfhf2
; F16C: fldt
; F16C-NEXT: fstps
; F16C-NEXT: vmovss
; F16C-NEXT: vcvtps2ph $0, %xmm0, %xmm0
; AVX: callq {{_+}}truncxfhf2
; ALL: ret
entry:
%0 = tail call i16 @llvm.convert.to.fp16.f80(x86_fp80 %d)
ret i16 %0
}
define zeroext i16 @test1(double %d) #1 {
; ALL-LABEL: test1:
; ALL: callq {{_+}}truncdfhf2
; ALL: ret
entry:
%0 = tail call i16 @llvm.convert.to.fp16.f64(double %d)
ret i16 %0
}
define zeroext i16 @test2(x86_fp80 %d) #1 {
; ALL-LABEL: test2:
; ALL: callq {{_+}}truncxfhf2
; ALL: ret
entry:
%0 = tail call i16 @llvm.convert.to.fp16.f80(x86_fp80 %d)
ret i16 %0
}
declare i16 @llvm.convert.to.fp16.f64(double)
declare i16 @llvm.convert.to.fp16.f80(x86_fp80)
attributes #0 = { nounwind readnone uwtable "unsafe-fp-math"="true" "use-soft-float"="false" }
attributes #1 = { nounwind readnone uwtable "unsafe-fp-math"="false" "use-soft-float"="false" }