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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=x86_64-unknown-unknown < %s | FileCheck %s
; cmp with single-use load, should not form branch.
define i32 @test1(double %a, double* nocapture %b, i32 %x, i32 %y) {
; CHECK-LABEL: test1:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %esi, %eax
; CHECK-NEXT: ucomisd (%rdi), %xmm0
; CHECK-NEXT: cmovbel %edx, %eax
; CHECK-NEXT: retq
%load = load double, double* %b, align 8
%cmp = fcmp olt double %load, %a
%cond = select i1 %cmp, i32 %x, i32 %y
ret i32 %cond
}
; Sanity check: no load.
define i32 @test2(double %a, double %b, i32 %x, i32 %y) {
; CHECK-LABEL: test2:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: ucomisd %xmm1, %xmm0
; CHECK-NEXT: cmovbel %esi, %eax
; CHECK-NEXT: retq
%cmp = fcmp ogt double %a, %b
%cond = select i1 %cmp, i32 %x, i32 %y
ret i32 %cond
}
; Multiple uses of the load.
define i32 @test4(i32 %a, i32* nocapture %b, i32 %x, i32 %y) {
; CHECK-LABEL: test4:
; CHECK: # %bb.0:
; CHECK-NEXT: movl (%rsi), %eax
; CHECK-NEXT: cmpl %edi, %eax
; CHECK-NEXT: cmovael %ecx, %edx
; CHECK-NEXT: addl %edx, %eax
; CHECK-NEXT: retq
%load = load i32, i32* %b, align 4
%cmp = icmp ult i32 %load, %a
%cond = select i1 %cmp, i32 %x, i32 %y
%add = add i32 %cond, %load
ret i32 %add
}
; Multiple uses of the cmp.
define i32 @test5(i32 %a, i32* nocapture %b, i32 %x, i32 %y) {
; CHECK-LABEL: test5:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %ecx, %eax
; CHECK-NEXT: cmpl %edi, (%rsi)
; CHECK-NEXT: cmoval %edi, %eax
; CHECK-NEXT: cmovael %edx, %eax
; CHECK-NEXT: retq
%load = load i32, i32* %b, align 4
%cmp = icmp ult i32 %load, %a
%cmp1 = icmp ugt i32 %load, %a
%cond = select i1 %cmp1, i32 %a, i32 %y
%cond5 = select i1 %cmp, i32 %cond, i32 %x
ret i32 %cond5
}
; Zero-extended select.
define void @test6(i32 %a, i32 %x, i32* %y.ptr, i64* %z.ptr) {
; CHECK-LABEL: test6:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: # kill: def $esi killed $esi def $rsi
; CHECK-NEXT: testl %edi, %edi
; CHECK-NEXT: cmovnsl (%rdx), %esi
; CHECK-NEXT: movq %rsi, (%rcx)
; CHECK-NEXT: retq
entry:
%y = load i32, i32* %y.ptr
%cmp = icmp slt i32 %a, 0
%z = select i1 %cmp, i32 %x, i32 %y
%z.ext = zext i32 %z to i64
store i64 %z.ext, i64* %z.ptr
ret void
}
; If a select is not obviously predictable, don't turn it into a branch.
define i32 @weighted_select1(i32 %a, i32 %b) {
; CHECK-LABEL: weighted_select1:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %esi, %eax
; CHECK-NEXT: testl %edi, %edi
; CHECK-NEXT: cmovnel %edi, %eax
; CHECK-NEXT: retq
%cmp = icmp ne i32 %a, 0
%sel = select i1 %cmp, i32 %a, i32 %b, !prof !0
ret i32 %sel
}
; If a select is obviously predictable, turn it into a branch.
define i32 @weighted_select2(i32 %a, i32 %b) {
; CHECK-LABEL: weighted_select2:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: testl %edi, %edi
; CHECK-NEXT: jne .LBB6_2
; CHECK-NEXT: # %bb.1: # %select.false
; CHECK-NEXT: movl %esi, %eax
; CHECK-NEXT: .LBB6_2: # %select.end
; CHECK-NEXT: retq
%cmp = icmp ne i32 %a, 0
%sel = select i1 %cmp, i32 %a, i32 %b, !prof !1
ret i32 %sel
}
; Note the reversed profile weights: it doesn't matter if it's
; obviously true or obviously false.
; Either one should become a branch rather than conditional move.
; TODO: But likely true vs. likely false should affect basic block placement?
define i32 @weighted_select3(i32 %a, i32 %b) {
; CHECK-LABEL: weighted_select3:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: testl %edi, %edi
; CHECK-NEXT: je .LBB7_1
; CHECK-NEXT: # %bb.2: # %select.end
; CHECK-NEXT: retq
; CHECK-NEXT: .LBB7_1: # %select.false
; CHECK-NEXT: movl %esi, %eax
; CHECK-NEXT: retq
%cmp = icmp ne i32 %a, 0
%sel = select i1 %cmp, i32 %a, i32 %b, !prof !2
ret i32 %sel
}
; Weightlessness is no reason to die.
define i32 @unweighted_select(i32 %a, i32 %b) {
; CHECK-LABEL: unweighted_select:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %esi, %eax
; CHECK-NEXT: testl %edi, %edi
; CHECK-NEXT: cmovnel %edi, %eax
; CHECK-NEXT: retq
%cmp = icmp ne i32 %a, 0
%sel = select i1 %cmp, i32 %a, i32 %b, !prof !3
ret i32 %sel
}
!0 = !{!"branch_weights", i32 1, i32 99}
!1 = !{!"branch_weights", i32 1, i32 100}
!2 = !{!"branch_weights", i32 100, i32 1}
!3 = !{!"branch_weights", i32 0, i32 0}
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