; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx | FileCheck %s declare double @sin(double %f) ; When the subs are strict, they can't be removed because of signed zero. define double @strict(double %e) nounwind { ; CHECK-LABEL: strict: ; CHECK: # %bb.0: ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm1 ; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm0 ; CHECK-NEXT: callq sin@PLT ; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm1 ; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm0 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: retq %f = fsub double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub double 0.0, %g ret double %h } ; 'fast' implies no-signed-zeros, so the negates fold away. ; The 'sin' does not need any fast-math-flags for this transform. define double @fast(double %e) nounwind { ; CHECK-LABEL: fast: ; CHECK: # %bb.0: ; CHECK-NEXT: jmp sin@PLT # TAILCALL %f = fsub fast double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub fast double 0.0, %g ret double %h } ; No-signed-zeros is all that we need for this transform. define double @nsz(double %e) nounwind { ; CHECK-LABEL: nsz: ; CHECK: # %bb.0: ; CHECK-NEXT: jmp sin@PLT # TAILCALL %f = fsub nsz double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub nsz double 0.0, %g ret double %h } ; The 1st negate is strict, so we can't kill that sub, but the 2nd disappears. define double @semi_strict1(double %e) nounwind { ; CHECK-LABEL: semi_strict1: ; CHECK: # %bb.0: ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm1 ; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm0 ; CHECK-NEXT: callq sin@PLT ; CHECK-NEXT: vxorpd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0, %xmm0 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: retq %f = fsub double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub nsz double 0.0, %g ret double %h } ; The 2nd negate is strict, so we can't kill it. It becomes an add of zero instead. define double @semi_strict2(double %e) nounwind { ; CHECK-LABEL: semi_strict2: ; CHECK: # %bb.0: ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: callq sin@PLT ; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm1 ; CHECK-NEXT: vaddsd %xmm1, %xmm0, %xmm0 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: retq %f = fsub nsz double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub double 0.0, %g ret double %h } ; FIXME: ; Auto-upgrade function attribute to IR-level fast-math-flags. define double @fn_attr(double %e) nounwind #0 { ; CHECK-LABEL: fn_attr: ; CHECK: # %bb.0: ; CHECK-NEXT: jmp sin@PLT # TAILCALL %f = fsub double 0.0, %e %g = call double @sin(double %f) readonly %h = fsub double 0.0, %g ret double %h } attributes #0 = { "unsafe-fp-math"="true" "no-signed-zeros-fp-math"="true" }