Tamar Christina <tamar.christ...@arm.com> writes:
> Hi All,
>
> Recently something in the midend had started inverting the branches by
> inverting
> the condition and the branches.
>
> While this is fine, it makes it hard to actually test. In RTL I disable
> scheduling and BB reordering to prevent this. But in GIMPLE there seems to be
> nothing I can do. __builtin_expect seems to have no impact on the change
> since
> I suspect this is happening during expand where conditions can be flipped
> regardless of probability during compare_and_branch.
>
> Since the mid-end has plenty of correctness tests, this weakens the backend
> tests to just check that a correct looking sequence is emitted.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/testsuite/ChangeLog:
>
> PR testsuite/113502
> * gcc.target/aarch64/sve/vect-early-break-cbranch.c: Ignore exact
> branch.
> * gcc.target/aarch64/vect-early-break-cbranch.c: Likewise.
OK I guess, since I agree that the "polarity" of the branch isn't really the
thing that we're trying to test. But the fact that even __builtin_expect
doesn't work seems like a bug. Do we have a PR for that? Might be worth
filing one (for GCC 15+) if we don't.
Thanks,
Richard
>
> --- inline copy of patch --
> diff --git a/gcc/testsuite/gcc.target/aarch64/sve/vect-early-break-cbranch.c
> b/gcc/testsuite/gcc.target/aarch64/sve/vect-early-break-cbranch.c
> index
> d15053553f94e7dce3540e21f0c1f0d39ea4f289..d7cef1105410be04ed67d1d3b800746267f205a8
> 100644
> --- a/gcc/testsuite/gcc.target/aarch64/sve/vect-early-break-cbranch.c
> +++ b/gcc/testsuite/gcc.target/aarch64/sve/vect-early-break-cbranch.c
> @@ -9,7 +9,7 @@ int b[N] = {0};
> ** ...
> ** cmpgt p[0-9]+.s, p[0-9]+/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any \.L[0-9]+
> +** b.(any|none) \.L[0-9]+
> ** ...
> */
> void f1 ()
> @@ -26,7 +26,7 @@ void f1 ()
> ** ...
> ** cmpge p[0-9]+.s, p[0-9]+/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any \.L[0-9]+
> +** b.(any|none) \.L[0-9]+
> ** ...
> */
> void f2 ()
> @@ -43,7 +43,7 @@ void f2 ()
> ** ...
> ** cmpeq p[0-9]+.s, p[0-9]+/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any \.L[0-9]+
> +** b.(any|none) \.L[0-9]+
> ** ...
> */
> void f3 ()
> @@ -60,7 +60,7 @@ void f3 ()
> ** ...
> ** cmpne p[0-9]+.s, p[0-9]+/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any \.L[0-9]+
> +** b.(any|none) \.L[0-9]+
> ** ...
> */
> void f4 ()
> @@ -77,7 +77,7 @@ void f4 ()
> ** ...
> ** cmplt p[0-9]+.s, p7/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any .L[0-9]+
> +** b.(any|none) .L[0-9]+
> ** ...
> */
> void f5 ()
> @@ -94,7 +94,7 @@ void f5 ()
> ** ...
> ** cmple p[0-9]+.s, p[0-9]+/z, z[0-9]+.s, #0
> ** ptest p[0-9]+, p[0-9]+.b
> -** b.any \.L[0-9]+
> +** b.(any|none) \.L[0-9]+
> ** ...
> */
> void f6 ()
> diff --git a/gcc/testsuite/gcc.target/aarch64/vect-early-break-cbranch.c
> b/gcc/testsuite/gcc.target/aarch64/vect-early-break-cbranch.c
> index
> a5e7b94827dd70240d754a834f1d11750a9c27a9..673b781eb6d092f6311409797b20a971f4fae247
> 100644
> --- a/gcc/testsuite/gcc.target/aarch64/vect-early-break-cbranch.c
> +++ b/gcc/testsuite/gcc.target/aarch64/vect-early-break-cbranch.c
> @@ -15,7 +15,7 @@ int b[N] = {0};
> ** cmgt v[0-9]+.4s, v[0-9]+.4s, #0
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f1 ()
> @@ -34,7 +34,7 @@ void f1 ()
> ** cmge v[0-9]+.4s, v[0-9]+.4s, #0
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f2 ()
> @@ -53,7 +53,7 @@ void f2 ()
> ** cmeq v[0-9]+.4s, v[0-9]+.4s, #0
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f3 ()
> @@ -72,7 +72,7 @@ void f3 ()
> ** cmtst v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f4 ()
> @@ -91,7 +91,7 @@ void f4 ()
> ** cmlt v[0-9]+.4s, v[0-9]+.4s, #0
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f5 ()
> @@ -110,7 +110,7 @@ void f5 ()
> ** cmle v[0-9]+.4s, v[0-9]+.4s, #0
> ** umaxp v[0-9]+.4s, v[0-9]+.4s, v[0-9]+.4s
> ** fmov x[0-9]+, d[0-9]+
> -** cbnz x[0-9]+, \.L[0-9]+
> +** cbn?z x[0-9]+, \.L[0-9]+
> ** ...
> */
> void f6 ()
