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|
; RUN: opt < %s -simplifycfg -S | FileCheck %s
; Test basic folding to a conditional branch.
define i32 @foo(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @foo(
entry:
%eq = icmp eq i64 %x, %y
br i1 %eq, label %b, label %switch
switch:
%lt = icmp slt i64 %x, %y
; CHECK: br i1 %lt, label %a, label %b
%qux = select i1 %lt, i32 0, i32 2
switch i32 %qux, label %bees [
i32 0, label %a
i32 1, label %b
i32 2, label %b
]
a:
tail call void @bees.a() nounwind
ret i32 1
; CHECK: b:
; CHECK-NEXT: %retval = phi i32 [ 0, %switch ], [ 2, %entry ]
b:
%retval = phi i32 [0, %switch], [0, %switch], [2, %entry]
tail call void @bees.b() nounwind
ret i32 %retval
; CHECK-NOT: bees:
bees:
tail call void @llvm.trap() nounwind
unreachable
}
; Test basic folding to an unconditional branch.
define i32 @bar(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @bar(
entry:
; CHECK-NEXT: entry:
; CHECK-NEXT: tail call void @bees.a() [[NUW:#[0-9]+]]
; CHECK-NEXT: ret i32 0
%lt = icmp slt i64 %x, %y
%qux = select i1 %lt, i32 0, i32 2
switch i32 %qux, label %bees [
i32 0, label %a
i32 1, label %b
i32 2, label %a
]
a:
%retval = phi i32 [0, %entry], [0, %entry], [1, %b]
tail call void @bees.a() nounwind
ret i32 0
b:
tail call void @bees.b() nounwind
br label %a
bees:
tail call void @llvm.trap() nounwind
unreachable
}
; Test the edge case where both values from the select are the default case.
define void @bazz(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @bazz(
entry:
; CHECK-NEXT: entry:
; CHECK-NEXT: tail call void @bees.b() [[NUW]]
; CHECK-NEXT: ret void
%lt = icmp slt i64 %x, %y
%qux = select i1 %lt, i32 10, i32 12
switch i32 %qux, label %b [
i32 0, label %a
i32 1, label %bees
i32 2, label %bees
]
a:
tail call void @bees.a() nounwind
ret void
b:
tail call void @bees.b() nounwind
ret void
bees:
tail call void @llvm.trap()
unreachable
}
; Test the edge case where both values from the select are equal.
define void @quux(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @quux(
entry:
; CHECK-NEXT: entry:
; CHECK-NEXT: tail call void @bees.a() [[NUW]]
; CHECK-NEXT: ret void
%lt = icmp slt i64 %x, %y
%qux = select i1 %lt, i32 0, i32 0
switch i32 %qux, label %b [
i32 0, label %a
i32 1, label %bees
i32 2, label %bees
]
a:
tail call void @bees.a() nounwind
ret void
b:
tail call void @bees.b() nounwind
ret void
bees:
tail call void @llvm.trap()
unreachable
}
; A final test, for phi node munging.
define i32 @xyzzy(i64 %x, i64 %y) {
; CHECK-LABEL: @xyzzy(
entry:
%eq = icmp eq i64 %x, %y
br i1 %eq, label %r, label %cont
cont:
; CHECK: %lt = icmp slt i64 %x, %y
%lt = icmp slt i64 %x, %y
; CHECK-NEXT: select i1 %lt, i32 -1, i32 1
%qux = select i1 %lt, i32 0, i32 2
switch i32 %qux, label %bees [
i32 0, label %a
i32 1, label %r
i32 2, label %r
]
r:
%val = phi i32 [0, %entry], [1, %cont], [1, %cont]
ret i32 %val
a:
ret i32 -1
; CHECK-NOT: bees:
bees:
tail call void @llvm.trap()
unreachable
}
declare void @llvm.trap() nounwind noreturn
declare void @bees.a() nounwind
declare void @bees.b() nounwind
; CHECK: attributes [[NUW]] = { nounwind }
; CHECK: attributes #1 = { noreturn nounwind }
|
