From e1d0fa1c2288e7141ee86c0c82093d75500ea144 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 7 Mar 2009 23:32:02 +0000 Subject: fix a serious pessimization that Tron on IRC pointed out where we would "boolify" pointers, generating really awful code because getting the pointer value requires a load itself. Before: _foo: movb $1, _X.b ret _get: xorl %ecx, %ecx movb _X.b, %al testb %al, %al movl $_Y, %eax cmove %ecx, %eax ret With the xform disabled: _foo: movl $_Y, _X ret _get: movl _X, %eax ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66351 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll (limited to 'test/Transforms/GlobalOpt') diff --git a/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll b/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll new file mode 100644 index 0000000..8dba5b1 --- /dev/null +++ b/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll @@ -0,0 +1,17 @@ +; RUN: llvm-as < %s | opt -globalopt | llvm-dis | grep {@X = internal global i32} +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" +target triple = "i386-apple-darwin7" +@X = internal global i32* null ; [#uses=2] +@Y = internal global i32 0 ; [#uses=1] + +define void @foo() nounwind { +entry: + store i32* @Y, i32** @X, align 4 + ret void +} + +define i32* @get() nounwind { +entry: + %0 = load i32** @X, align 4 ; [#uses=1] + ret i32* %0 +} -- cgit v1.1