[PATCH] D124228: [NFC][NewGVN][LoadCoercion] Add new tests for future commit

[Konstantina Mitropoulou via Phabricator via llvm-commits]

kmitropoulou added a comment.

In D124228#3584866 <https://reviews.llvm.org/D124228#3584866>, @foad wrote:

> In D124228#3583946 <https://reviews.llvm.org/D124228#3583946>, @kmitropoulou wrote:
>
>> In D124228#3577317 <https://reviews.llvm.org/D124228#3577317>, @foad wrote:
>>
>>> LGTM. Could also use a common "GVN" prefix if you want (and if there are any tests at all where old and new gvn produce the same result).
>>
>> I am not sure what you mean. The old and new GVN might not have exactly the same output for load coercion e.g. in https://reviews.llvm.org/D124230 - test5, test 6 and test8 .
>
> I mean if you write the RUN lines like this then update_test_checks is clever enough to use the GVN prefix if both passes produce identical results for a particular function, or separate OLDGVN and NEWGVN and prefixes if they produce different results:
>
>   ; RUN: opt -S -gvn < %s | FileCheck %s -check-prefixes=GVN,OLDGVN
>   ; RUN: opt -S -newgvn < %s | FileCheck %s -check-prefixes=GVN,NEWGVN
>
> For example, at the moment I get different results on test1:
>
>   define i8 @test1(i32* %P1) {
>   ; OLDGVN-LABEL: @test1(
>   ; OLDGVN-NEXT:    [[V1:%.*]] = load i32, i32* [[P1:%.*]], align 4
>   ; OLDGVN-NEXT:    [[P2:%.*]] = bitcast i32* [[P1]] to i8*
>   ; OLDGVN-NEXT:    [[TMP1:%.*]] = trunc i32 [[V1]] to i8
>   ; OLDGVN-NEXT:    [[V4:%.*]] = add i8 [[TMP1]], [[TMP1]]
>   ; OLDGVN-NEXT:    ret i8 [[V4]]
>   ;
>   ; NEWGVN-LABEL: @test1(
>   ; NEWGVN-NEXT:    [[V1:%.*]] = load i32, i32* [[P1:%.*]], align 4
>   ; NEWGVN-NEXT:    [[P2:%.*]] = bitcast i32* [[P1]] to i8*
>   ; NEWGVN-NEXT:    [[V2:%.*]] = load i8, i8* [[P2]], align 1
>   ; NEWGVN-NEXT:    [[V3:%.*]] = trunc i32 [[V1]] to i8
>   ; NEWGVN-NEXT:    [[V4:%.*]] = add i8 [[V2]], [[V3]]
>   ; NEWGVN-NEXT:    ret i8 [[V4]]
>   ;
>     %V1 = load i32, i32* %P1
>     %P2 = bitcast i32* %P1 to i8*
>     %V2 = load i8, i8* %P2
>     %V3 = trunc i32 %V1 to i8
>     %V4 = add i8 %V2, %V3
>     ret i8 %V4
>   }
>
> but identical results on test4:
>
>   define <{<2 x i32>, i32}> @test4(i8* %P) {
>   ; GVN-LABEL: @test4(
>   ; GVN-NEXT:  Entry:
>   ; GVN-NEXT:    [[P2:%.*]] = bitcast i8* [[P:%.*]] to i32*
>   ; GVN-NEXT:    [[V2:%.*]] = load i32, i32* [[P2]], align 4
>   ; GVN-NEXT:    [[P1:%.*]] = bitcast i8* [[P]] to <2 x i32>*
>   ; GVN-NEXT:    [[V1:%.*]] = load <2 x i32>, <2 x i32>* [[P1]], align 8
>   ; GVN-NEXT:    [[I1:%.*]] = insertvalue <{ <2 x i32>, i32 }> poison, <2 x i32> [[V1]], 0
>   ; GVN-NEXT:    [[I2:%.*]] = insertvalue <{ <2 x i32>, i32 }> [[I1]], i32 [[V2]], 1
>   ; GVN-NEXT:    ret <{ <2 x i32>, i32 }> [[I2]]
>   ;
>   Entry:
>     %P2 = bitcast i8* %P to i32*
>     %V2 = load i32, i32* %P2
>     %P1 = bitcast i8* %P to <2 x i32>*
>     %V1 = load <2 x i32>, <2 x i32>* %P1
>     %I1 = insertvalue <{<2 x i32>, i32}> poison, <2 x i32> %V1, 0
>     %I2 = insertvalue <{<2 x i32>, i32}> %I1, i32 %V2, 1
>     ret <{<2 x i32>, i32}> %I2
>   }
>
> I think this is nice because it is really easy to see where the remaining differences are.

Thanks Jay :) I am going to update all the tests.


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