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1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py2; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx | FileCheck %s3 4declare double @sin(double %f)5 6; When the subs are strict, they can't be removed because of signed zero.7 8define double @strict(double %e) nounwind {9; CHECK-LABEL: strict:10; CHECK: # %bb.0:11; CHECK-NEXT: pushq %rax12; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm113; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm014; CHECK-NEXT: callq sin@PLT15; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm116; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm017; CHECK-NEXT: popq %rax18; CHECK-NEXT: retq19 %f = fsub double 0.0, %e20 %g = call double @sin(double %f) readonly21 %h = fsub double 0.0, %g22 ret double %h23}24 25; 'fast' implies no-signed-zeros, so the negates fold away.26; The 'sin' does not need any fast-math-flags for this transform.27 28define double @fast(double %e) nounwind {29; CHECK-LABEL: fast:30; CHECK: # %bb.0:31; CHECK-NEXT: jmp sin@PLT # TAILCALL32 %f = fsub fast double 0.0, %e33 %g = call double @sin(double %f) readonly34 %h = fsub fast double 0.0, %g35 ret double %h36}37 38; No-signed-zeros is all that we need for this transform.39 40define double @nsz(double %e) nounwind {41; CHECK-LABEL: nsz:42; CHECK: # %bb.0:43; CHECK-NEXT: jmp sin@PLT # TAILCALL44 %f = fsub nsz double 0.0, %e45 %g = call double @sin(double %f) readonly46 %h = fsub nsz double 0.0, %g47 ret double %h48}49 50; The 1st negate is strict, so we can't kill that sub, but the 2nd disappears.51 52define double @semi_strict1(double %e) nounwind {53; CHECK-LABEL: semi_strict1:54; CHECK: # %bb.0:55; CHECK-NEXT: pushq %rax56; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm157; CHECK-NEXT: vsubsd %xmm0, %xmm1, %xmm058; CHECK-NEXT: callq sin@PLT59; CHECK-NEXT: vxorpd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0, %xmm060; CHECK-NEXT: popq %rax61; CHECK-NEXT: retq62 %f = fsub double 0.0, %e63 %g = call double @sin(double %f) readonly64 %h = fsub nsz double 0.0, %g65 ret double %h66}67 68; The 2nd negate is strict, so we can't kill it. It becomes an add of zero instead.69 70define double @semi_strict2(double %e) nounwind {71; CHECK-LABEL: semi_strict2:72; CHECK: # %bb.0:73; CHECK-NEXT: pushq %rax74; CHECK-NEXT: callq sin@PLT75; CHECK-NEXT: vxorpd %xmm1, %xmm1, %xmm176; CHECK-NEXT: vaddsd %xmm1, %xmm0, %xmm077; CHECK-NEXT: popq %rax78; CHECK-NEXT: retq79 %f = fsub nsz double 0.0, %e80 %g = call double @sin(double %f) readonly81 %h = fsub double 0.0, %g82 ret double %h83}84 85define double @nsz_flag(double %e) nounwind {86; CHECK-LABEL: nsz_flag:87; CHECK: # %bb.0:88; CHECK-NEXT: jmp sin@PLT # TAILCALL89 %f = fsub nsz double 0.0, %e90 %g = call nsz double @sin(double %f) readonly91 %h = fsub nsz double 0.0, %g92 ret double %h93}94 95