| ; RUN: opt < %s -jump-threading -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() |
