; RUN: llc -o - -verify-machineinstrs %s | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" @data = external global [3 x i32], align 4 @store = external global i32, align 4 ; %else1 and %then2 end up lowering to identical blocks. These blocks should be ; merged during tail-merging. ; CHECK-LABEL: merge_identical_blocks ; CHECK: movl $data+4 ; CHECK-NOT: movl $data+4 ; CHECK: retq define void @merge_identical_blocks(i1 %a, i1 %b) { entry: br label %if1 if1: ; predfs = %entry br i1 %a, label %else1, label %if2 else1: ; preds = %if1 %ptr.else1 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 1 br label %phi_join if2: ; preds = %if1 br i1 %b, label %then2, label %else2 then2: ; preds = %if2 %ptr.then2 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 1 br label %phi_join else2: ; preds = %if2 %ptr.else2 = getelementptr inbounds [3 x i32], [3 x i32]* @data, i64 0, i32 2 br label %phi_join phi_join: ; preds = %else1, %then2, %else2 %val.ptr = phi i32* [ %ptr.else1, %else1 ], [ %ptr.then2, %then2 ], [ %ptr.else2, %else2 ] %val = load i32, i32* %val.ptr, align 4 store i32 %val, i32* @store, align 4 ret void }