From 2249a0b1bd0941e61c0b87f2f64a5c8cab45f14c Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 12 Jan 2010 02:07:17 +0000 Subject: Teach jump threading to duplicate small blocks when the branch condition is a xor with a phi node. This eliminates nonsense like this from 176.gcc in several places: LBB166_84: testl %eax, %eax - setne %al - xorb %cl, %al - notb %al - testb $1, %al - je LBB166_85 + je LBB166_69 + jmp LBB166_85 This is rdar://7391699 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93221 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/JumpThreading/basic.ll | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) (limited to 'test/Transforms/JumpThreading/basic.ll') diff --git a/test/Transforms/JumpThreading/basic.ll b/test/Transforms/JumpThreading/basic.ll index ac31cdb..34b4243 100644 --- a/test/Transforms/JumpThreading/basic.ll +++ b/test/Transforms/JumpThreading/basic.ll @@ -383,11 +383,11 @@ return: } -;;; Duplicate condition to avoid xor of cond. -;;; TODO: Make this happen. -define i32 @testXX(i1 %cond, i1 %cond2) { +;; Duplicate condition to avoid xor of cond. +;; rdar://7391699 +define i32 @test13(i1 %cond, i1 %cond2) { Entry: -; CHECK: @testXX +; CHECK: @test13 %v1 = call i32 @f1() br i1 %cond, label %Merge, label %F1 @@ -396,7 +396,8 @@ F1: Merge: %B = phi i1 [true, %Entry], [%cond2, %F1] - %M = icmp eq i32 %v1, 192 + %C = phi i32 [192, %Entry], [%v1, %F1] + %M = icmp eq i32 %C, 192 %N = xor i1 %B, %M br i1 %N, label %T2, label %F2 @@ -405,6 +406,18 @@ T2: F2: ret i32 %v1 + +;; FIXME: CONSTANT FOLD on clone and when phi gets eliminated. + +; CHECK: Entry.Merge_crit_edge: +; CHECK-NEXT: %M1 = icmp eq i32 192, 192 +; CHECK-NEXT: %N2 = xor i1 true, %M1 +; CHECK-NEXT: br i1 %N2, label %T2, label %F2 + +; CHECK: Merge: +; CHECK-NEXT: %M = icmp eq i32 %v1, 192 +; CHECK-NEXT: %N = xor i1 %cond2, %M +; CHECK-NEXT: br i1 %N, label %T2, label %F2 } -- cgit v1.1