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; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mcpu=x86-64 | FileCheck %s
; More than one 'arcp' division using a single divisor operand
; should be converted into a reciprocal and multiplication.
; Don't do anything for just one division.
define float @div1_arcp(float %x, float %y, float %z) {
; CHECK-LABEL: div1_arcp:
; CHECK: # BB#0:
; CHECK-NEXT: divss %xmm1, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv arcp float %x, %y
ret float %div1
}
; All math instructions are 'arcp', so optimize.
define float @div2_arcp_all(float %x, float %y, float %z) {
; CHECK-LABEL: div2_arcp_all:
; CHECK: # BB#0:
; CHECK-NEXT: movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
; CHECK-NEXT: divss %xmm2, %xmm3
; CHECK-NEXT: mulss %xmm3, %xmm0
; CHECK-NEXT: mulss %xmm1, %xmm0
; CHECK-NEXT: mulss %xmm3, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv arcp float %x, %z
%mul = fmul arcp float %div1, %y
%div2 = fdiv arcp float %mul, %z
ret float %div2
}
; The first division is not 'arcp', so do not optimize.
define float @div2_arcp_partial1(float %x, float %y, float %z) {
; CHECK-LABEL: div2_arcp_partial1:
; CHECK: # BB#0:
; CHECK-NEXT: divss %xmm2, %xmm0
; CHECK-NEXT: mulss %xmm1, %xmm0
; CHECK-NEXT: divss %xmm2, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv float %x, %z
%mul = fmul arcp float %div1, %y
%div2 = fdiv arcp float %mul, %z
ret float %div2
}
; The second division is not 'arcp', so do not optimize.
define float @div2_arcp_partial2(float %x, float %y, float %z) {
; CHECK-LABEL: div2_arcp_partial2:
; CHECK: # BB#0:
; CHECK-NEXT: divss %xmm2, %xmm0
; CHECK-NEXT: mulss %xmm1, %xmm0
; CHECK-NEXT: divss %xmm2, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv arcp float %x, %z
%mul = fmul arcp float %div1, %y
%div2 = fdiv float %mul, %z
ret float %div2
}
; The multiply is not 'arcp', but that does not prevent optimizing the divisions.
define float @div2_arcp_partial3(float %x, float %y, float %z) {
; CHECK-LABEL: div2_arcp_partial3:
; CHECK: # BB#0:
; CHECK-NEXT: movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
; CHECK-NEXT: divss %xmm2, %xmm3
; CHECK-NEXT: mulss %xmm3, %xmm0
; CHECK-NEXT: mulss %xmm1, %xmm0
; CHECK-NEXT: mulss %xmm3, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv arcp float %x, %z
%mul = fmul float %div1, %y
%div2 = fdiv arcp float %mul, %z
ret float %div2
}
; If the reciprocal is already calculated, we should not
; generate an extra multiplication by 1.0.
define double @div3_arcp(double %x, double %y, double %z) {
; CHECK-LABEL: div3_arcp:
; CHECK: # BB#0:
; CHECK-NEXT: movsd{{.*#+}} xmm2 = mem[0],zero
; CHECK-NEXT: divsd %xmm1, %xmm2
; CHECK-NEXT: mulsd %xmm2, %xmm0
; CHECK-NEXT: addsd %xmm2, %xmm0
; CHECK-NEXT: retq
%div1 = fdiv fast double 1.0, %y
%div2 = fdiv fast double %x, %y
%ret = fadd fast double %div2, %div1
ret double %ret
}
define void @PR24141() {
; CHECK-LABEL: PR24141:
; CHECK: callq
; CHECK-NEXT: divsd
; CHECK-NEXT: jmp
entry:
br label %while.body
while.body:
%x.0 = phi double [ undef, %entry ], [ %div, %while.body ]
%call = call { double, double } @g(double %x.0)
%xv0 = extractvalue { double, double } %call, 0
%xv1 = extractvalue { double, double } %call, 1
%div = fdiv arcp double %xv0, %xv1
br label %while.body
}
declare { double, double } @g(double)
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