+; RUN: opt -codegenprepare -S < %s | FileCheck %s
+
+target triple = "x86_64-unknown-unknown"
+
+; Nothing to sink here, but this gets converted to a branch to
+; avoid stalling an out-of-order CPU on a predictable branch.
+
+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: br i1 %cmp, label %select.end, label %select.false
+; CHECK: select.false:
+; CHECK: br label %select.end
+; CHECK: select.end:
+; CHECK: %sel = phi i32 [ %x, %entry ], [ %y, %select.false ]
+; 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
+}
+
+; 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
+}
+