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 } 42
