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; RUN: opt %s -simplifycfg -S | FileCheck %s
declare i32 @f(i32)
define i32 @basic(i32 %x) {
; CHECK-LABEL: @basic
; CHECK: x.off = add i32 %x, -5
; CHECK: %switch = icmp ult i32 %x.off, 3
; CHECK: br i1 %switch, label %a, label %default
entry:
switch i32 %x, label %default [
i32 5, label %a
i32 6, label %a
i32 7, label %a
]
default:
%0 = call i32 @f(i32 0)
ret i32 %0
a:
%1 = call i32 @f(i32 1)
ret i32 %1
}
define i32 @unreachable(i32 %x) {
; CHECK-LABEL: @unreachable
; CHECK: x.off = add i32 %x, -5
; CHECK: %switch = icmp ult i32 %x.off, 3
; CHECK: br i1 %switch, label %a, label %b
entry:
switch i32 %x, label %unreachable [
i32 5, label %a
i32 6, label %a
i32 7, label %a
i32 10, label %b
i32 20, label %b
i32 30, label %b
i32 40, label %b
]
unreachable:
unreachable
a:
%0 = call i32 @f(i32 0)
ret i32 %0
b:
%1 = call i32 @f(i32 1)
ret i32 %1
}
define i32 @unreachable2(i32 %x) {
; CHECK-LABEL: @unreachable2
; CHECK: x.off = add i32 %x, -5
; CHECK: %switch = icmp ult i32 %x.off, 3
; CHECK: br i1 %switch, label %a, label %b
entry:
; Note: folding the most popular case destination into the default
; would prevent switch-to-icmp here.
switch i32 %x, label %unreachable [
i32 5, label %a
i32 6, label %a
i32 7, label %a
i32 10, label %b
i32 20, label %b
]
unreachable:
unreachable
a:
%0 = call i32 @f(i32 0)
ret i32 %0
b:
%1 = call i32 @f(i32 1)
ret i32 %1
}
|
