forked from OSchip/llvm-project
65 lines
1.9 KiB
LLVM
65 lines
1.9 KiB
LLVM
; RUN: opt < %s -simplifycfg -S | FileCheck %s
|
|
|
|
; Skip simplifying unconditional branches from empty blocks in simplifyCFG,
|
|
; when it can destroy canonical loop structure.
|
|
|
|
; void foo();
|
|
; bool test(int a, int b, int *c) {
|
|
; bool changed = false;
|
|
; for (unsigned int i = 2; i--;) {
|
|
; int r = a | b;
|
|
; if ( r != c[i]) {
|
|
; c[i] = r;
|
|
; foo();
|
|
; changed = true;
|
|
; }
|
|
; }
|
|
; return changed;
|
|
; }
|
|
|
|
; CHECK-LABEL: @test(
|
|
; CHECK: for.cond:
|
|
; CHECK-NEXT: %i.0 = phi i32 [ 2, %entry ], [ %dec, %if.end ]
|
|
; CHECK: for.body:
|
|
; CHECK: br i1 %cmp, label %if.end, label %if.then
|
|
; CHECK-NOT: br i1 %cmp, label %for.cond, label %if.then
|
|
; CHECK: if.then:
|
|
; CHECK: br label %if.end
|
|
; CHECK-NOT: br label %for.cond
|
|
; CHECK: if.end:
|
|
; CHECK: br label %for.cond
|
|
define i1 @test(i32 %a, i32 %b, i32* %c) {
|
|
entry:
|
|
br label %for.cond
|
|
|
|
for.cond: ; preds = %if.end, %entry
|
|
%i.0 = phi i32 [ 2, %entry ], [ %dec, %if.end ]
|
|
%changed.0.off0 = phi i1 [ false, %entry ], [ %changed.1.off0, %if.end ]
|
|
%dec = add nsw i32 %i.0, -1
|
|
%tobool = icmp eq i32 %i.0, 0
|
|
br i1 %tobool, label %for.cond.cleanup, label %for.body
|
|
|
|
for.cond.cleanup: ; preds = %for.cond
|
|
%changed.0.off0.lcssa = phi i1 [ %changed.0.off0, %for.cond ]
|
|
ret i1 %changed.0.off0.lcssa
|
|
|
|
for.body: ; preds = %for.cond
|
|
%or = or i32 %a, %b
|
|
%idxprom = sext i32 %dec to i64
|
|
%arrayidx = getelementptr inbounds i32, i32* %c, i64 %idxprom
|
|
%0 = load i32, i32* %arrayidx, align 4
|
|
%cmp = icmp eq i32 %or, %0
|
|
br i1 %cmp, label %if.end, label %if.then
|
|
|
|
if.then: ; preds = %for.body
|
|
store i32 %or, i32* %arrayidx, align 4
|
|
call void @foo()
|
|
br label %if.end
|
|
|
|
if.end: ; preds = %for.body, %if.then
|
|
%changed.1.off0 = phi i1 [ true, %if.then ], [ %changed.0.off0, %for.body ]
|
|
br label %for.cond
|
|
}
|
|
|
|
declare void @foo()
|