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; RUN: opt -codegenprepare -S < %s | FileCheck %s
target triple = "x86_64-unknown-unknown"
; Nothing to sink and convert here.
define i32 @no_sink(double %a, double* %b, i32 %x, i32 %y) {
entry:
%load = load double, double* %b, align 8
%cmp = fcmp olt double %load, %a
%sel = select i1 %cmp, i32 %x, i32 %y
ret i32 %sel
; CHECK-LABEL: @no_sink(
; CHECK: %load = load double, double* %b, align 8
; CHECK: %cmp = fcmp olt double %load, %a
; CHECK: %sel = select i1 %cmp, i32 %x, i32 %y
; CHECK: ret i32 %sel
}
; An 'fdiv' is expensive, so sink it rather than speculatively execute it.
define float @fdiv_true_sink(float %a, float %b) {
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %div, float 2.0
ret float %sel
; CHECK-LABEL: @fdiv_true_sink(
; CHECK: %cmp = fcmp ogt float %a, 1.0
; CHECK: br i1 %cmp, label %select.true.sink, label %select.end
; CHECK: select.true.sink:
; CHECK: %div = fdiv float %a, %b
; CHECK: br label %select.end
; CHECK: select.end:
; CHECK: %sel = phi float [ %div, %select.true.sink ], [ 2.000000e+00, %entry ]
; CHECK: ret float %sel
}
define float @fdiv_false_sink(float %a, float %b) {
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 3.0
%sel = select i1 %cmp, float 4.0, float %div
ret float %sel
; CHECK-LABEL: @fdiv_false_sink(
; CHECK: %cmp = fcmp ogt float %a, 3.0
; CHECK: br i1 %cmp, label %select.end, label %select.false.sink
; CHECK: select.false.sink:
; CHECK: %div = fdiv float %a, %b
; CHECK: br label %select.end
; CHECK: select.end:
; CHECK: %sel = phi float [ 4.000000e+00, %entry ], [ %div, %select.false.sink ]
; CHECK: ret float %sel
}
define float @fdiv_both_sink(float %a, float %b) {
entry:
%div1 = fdiv float %a, %b
%div2 = fdiv float %b, %a
%cmp = fcmp ogt float %a, 5.0
%sel = select i1 %cmp, float %div1, float %div2
ret float %sel
; CHECK-LABEL: @fdiv_both_sink(
; CHECK: %cmp = fcmp ogt float %a, 5.0
; CHECK: br i1 %cmp, label %select.true.sink, label %select.false.sink
; CHECK: select.true.sink:
; CHECK: %div1 = fdiv float %a, %b
; CHECK: br label %select.end
; CHECK: select.false.sink:
; CHECK: %div2 = fdiv float %b, %a
; CHECK: br label %select.end
; CHECK: select.end:
; CHECK: %sel = phi float [ %div1, %select.true.sink ], [ %div2, %select.false.sink ]
; CHECK: ret float %sel
}
; But if the select is marked unpredictable, then don't turn it into a branch.
define float @unpredictable_select(float %a, float %b) {
; CHECK-LABEL: @unpredictable_select(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[DIV:%.*]] = fdiv float %a, %b
; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float %a, 1.000000e+00
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], float [[DIV]], float 2.000000e+00, !unpredictable !0
; CHECK-NEXT: ret float [[SEL]]
;
entry:
%div = fdiv float %a, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %div, float 2.0, !unpredictable !0
ret float %sel
}
!0 = !{}
; An 'fadd' is not too expensive, so it's ok to speculate.
define float @fadd_no_sink(float %a, float %b) {
%add = fadd float %a, %b
%cmp = fcmp ogt float 6.0, %a
%sel = select i1 %cmp, float %add, float 7.0
ret float %sel
; CHECK-LABEL: @fadd_no_sink(
; CHECK: %sel = select i1 %cmp, float %add, float 7.0
}
; Possible enhancement: sinkability is only calculated with the direct
; operand of the select, so we don't try to sink this. The fdiv cost is not
; taken into account.
define float @fdiv_no_sink(float %a, float %b) {
entry:
%div = fdiv float %a, %b
%add = fadd float %div, %b
%cmp = fcmp ogt float %a, 1.0
%sel = select i1 %cmp, float %add, float 8.0
ret float %sel
; CHECK-LABEL: @fdiv_no_sink(
; CHECK: %sel = select i1 %cmp, float %add, float 8.0
}
; Do not transform the CFG if the select operands may have side effects.
declare i64* @bar(i32, i32, i32)
declare i64* @baz(i32, i32, i32)
define i64* @calls_no_sink(i32 %in) {
%call1 = call i64* @bar(i32 1, i32 2, i32 3)
%call2 = call i64* @baz(i32 1, i32 2, i32 3)
%tobool = icmp ne i32 %in, 0
%sel = select i1 %tobool, i64* %call1, i64* %call2
ret i64* %sel
; CHECK-LABEL: @calls_no_sink(
; CHECK: %sel = select i1 %tobool, i64* %call1, i64* %call2
}
define i32 @sdiv_no_sink(i32 %a, i32 %b) {
%div1 = sdiv i32 %a, %b
%div2 = sdiv i32 %b, %a
%cmp = icmp sgt i32 %a, 5
%sel = select i1 %cmp, i32 %div1, i32 %div2
ret i32 %sel
; CHECK-LABEL: @sdiv_no_sink(
; CHECK: %sel = select i1 %cmp, i32 %div1, i32 %div2
}
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