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llvm-project/llvm/test/CodeGen/X86/copysign-constant-magnitude.ll

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[X86] Teach FCOPYSIGN lowering to recognize constant magnitudes. For code like: float foo(float x) { return copysign(1.0, x); } We used to generate: andps <-0.000000e+00,0,0,0>, %xmm0 movss <1.000000e+00>, %xmm1 andps <nan>, %xmm1 orps %xmm0, %xmm1 Basically doing an abs(1.0f) in the two middle instructions. We now generate: andps <-0.000000e+00,0,0,0>, %xmm0 orps <1.000000e+00,0,0,0>, %xmm0 Builds on cleanups r223415, r223542. rdar://19049548 Differential Revision: http://reviews.llvm.org/D6555 llvm-svn: 225357
2015-01-08 01:33:03 +08:00
; RUN: llc < %s | FileCheck %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
define void @test_copysign_const_magnitude_d(double %X) {
; CHECK: [[SIGNMASK:L.+]]:
; CHECK-NEXT: .quad -9223372036854775808 ## double -0.000000e+00
; CHECK-NEXT: .quad 0 ## double 0.000000e+00
; CHECK: [[ZERO:L.+]]:
; CHECK-NEXT: .space 16
; CHECK: [[ONE:L.+]]:
; CHECK-NEXT: .quad 4607182418800017408 ## double 1.000000e+00
; CHECK-NEXT: .quad 0 ## double 0.000000e+00
; CHECK-LABEL: test_copysign_const_magnitude_d:
; CHECK: id
%iX = call double @id_d(double %X)
; CHECK-NEXT: andpd [[SIGNMASK]](%rip), %xmm0
%d0 = call double @copysign(double 0.000000e+00, double %iX)
; CHECK-NEXT: id
%id0 = call double @id_d(double %d0)
; CHECK-NEXT: andpd [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orpd [[ZERO]](%rip), %xmm0
%dn0 = call double @copysign(double -0.000000e+00, double %id0)
; CHECK-NEXT: id
%idn0 = call double @id_d(double %dn0)
; CHECK-NEXT: andpd [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orpd [[ONE]](%rip), %xmm0
%d1 = call double @copysign(double 1.000000e+00, double %idn0)
; CHECK-NEXT: id
%id1 = call double @id_d(double %d1)
; CHECK-NEXT: andpd [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orpd [[ONE]](%rip), %xmm0
%dn1 = call double @copysign(double -1.000000e+00, double %id1)
; CHECK-NEXT: id
%idn1 = call double @id_d(double %dn1)
; CHECK: retq
ret void
}
define void @test_copysign_const_magnitude_f(float %X) {
; CHECK: [[SIGNMASK:L.+]]:
; CHECK-NEXT: .long 2147483648 ## float -0.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK: [[ZERO:L.+]]:
; CHECK-NEXT: .space 16
; CHECK: [[ONE:L.+]]:
; CHECK-NEXT: .long 1065353216 ## float 1.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK-NEXT: .long 0 ## float 0.000000e+00
; CHECK-LABEL: test_copysign_const_magnitude_f:
; CHECK: id
%iX = call float @id_f(float %X)
; CHECK-NEXT: andps [[SIGNMASK]](%rip), %xmm0
%d0 = call float @copysignf(float 0.000000e+00, float %iX)
; CHECK-NEXT: id
%id0 = call float @id_f(float %d0)
; CHECK-NEXT: andps [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orps [[ZERO]](%rip), %xmm0
%dn0 = call float @copysignf(float -0.000000e+00, float %id0)
; CHECK-NEXT: id
%idn0 = call float @id_f(float %dn0)
; CHECK-NEXT: andps [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orps [[ONE]](%rip), %xmm0
%d1 = call float @copysignf(float 1.000000e+00, float %idn0)
; CHECK-NEXT: id
%id1 = call float @id_f(float %d1)
; CHECK-NEXT: andps [[SIGNMASK]](%rip), %xmm0
; CHECK-NEXT: orps [[ONE]](%rip), %xmm0
%dn1 = call float @copysignf(float -1.000000e+00, float %id1)
; CHECK-NEXT: id
%idn1 = call float @id_f(float %dn1)
; CHECK: retq
ret void
}
declare double @copysign(double, double) nounwind readnone
declare float @copysignf(float, float) nounwind readnone
; Dummy identity functions, so we always have xmm0, and prevent optimizations.
declare double @id_d(double)
declare float @id_f(float)