| Kyle Butt | a12bd75 | 2017-04-10 22:28:12 +0000 | [diff] [blame^] | 1 | ; RUN: llc -o - -verify-machineinstrs %s | FileCheck %s |
| 2 | target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" |
| 3 | target triple = "x86_64-unknown-linux-gnu" |
| 4 | |
| 5 | @data = external global [3 x i32], align 4 |
| 6 | @store = external global i32, align 4 |
| 7 | |
| 8 | ; %else1 and %then2 end up lowering to identical blocks. These blocks should be |
| 9 | ; merged during tail-merging. |
| 10 | ; CHECK-LABEL: merge_identical_blocks |
| 11 | ; CHECK: movl $data+4 |
| 12 | ; CHECK-NOT: movl $data+4 |
| 13 | ; CHECK: retq |
| 14 | define void @merge_identical_blocks(i1 %a, i1 %b) { |
| 15 | entry: |
| 16 | br label %if1 |
| 17 | |
| 18 | if1: ; predfs = %entry |
| 19 | br i1 %a, label %else1, label %if2 |
| 20 | |
| 21 | else1: ; preds = %if1 |
| 22 | %ptr.else1 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 1 |
| 23 | br label %phi_join |
| 24 | |
| 25 | if2: ; preds = %if1 |
| 26 | br i1 %b, label %then2, label %else2 |
| 27 | |
| 28 | then2: ; preds = %if2 |
| 29 | %ptr.then2 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 1 |
| 30 | br label %phi_join |
| 31 | |
| 32 | else2: ; preds = %if2 |
| 33 | %ptr.else2 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 2 |
| 34 | br label %phi_join |
| 35 | |
| 36 | phi_join: ; preds = %else1, %then2, %else2 |
| 37 | %val.ptr = phi i32* [ %ptr.else1, %else1 ], [ %ptr.then2, %then2 ], [ %ptr.else2, %else2 ] |
| 38 | %val = load i32, i32* %val.ptr, align 4 |
| 39 | store i32 %val, i32* @store, align 4 |
| 40 | ret void |
| 41 | } |