llvm-project/llvm/test/Transforms/GVN/load-constant-mem.ll

; RUN: opt < %s -basicaa -gvn -instcombine -S | grep {ret i32 0}
; PR4189
@G = external constant [4 x i32]

define i32 @test(i8* %p, i32 %i) nounwind {
entry:
	%P = getelementptr [4 x i32]* @G, i32 0, i32 %i
	%A = load i32* %P
	store i8 4, i8* %p
	%B = load i32* %P
	%C = sub i32 %A, %B
	ret i32 %C
}
Make BasicAliasAnalysis a normal AliasAnalysis implementation which does normal initialization and normal chaining. Change the default AliasAnalysis implementation to NoAlias. Update StandardCompileOpts.h and friends to explicitly request BasicAliasAnalysis. Update tests to explicitly request -basicaa. llvm-svn: 116720 2010-10-19 02:04:47 +08:00			`; RUN: opt < %s -basicaa -gvn -instcombine -S \| grep {ret i32 0}`
make memdep use the getModRefInfo method for stores instead of the low-level alias() method, allowing it to reason more aggressively about pointers into constant memory. PR4189 llvm-svn: 72403 2009-05-26 05:28:56 +08:00			`; PR4189`
			`@G = external constant [4 x i32]`

			`define i32 @test(i8* %p, i32 %i) nounwind {`
			`entry:`
			`%P = getelementptr [4 x i32]* @G, i32 0, i32 %i`
			`%A = load i32* %P`
			`store i8 4, i8* %p`
			`%B = load i32* %P`
			`%C = sub i32 %A, %B`
			`ret i32 %C`
			`}`