| ; Test merging of blocks that only have PHI nodes in them. This tests the case | |
| ; where the mergedinto block doesn't have any PHI nodes, and is in fact | |
| ; dominated by the block-to-be-eliminated | |
| ; | |
| ; RUN: opt < %s -simplifycfg -S | not grep N: | |
| ; | |
| declare i1 @foo() | |
| define i32 @test(i1 %a, i1 %b) { | |
| %c = call i1 @foo() | |
| br i1 %c, label %N, label %P | |
| P: | |
| %d = call i1 @foo() | |
| br i1 %d, label %N, label %Q | |
| Q: | |
| br label %N | |
| N: | |
| %W = phi i32 [0, %0], [1, %Q], [2, %P] | |
| ; This block should be foldable into M | |
| br label %M | |
| M: | |
| %R = add i32 %W, 1 | |
| ret i32 %R | |
| } | |