[PATCH][GCC][Arm] Missing optimization pattern for rev16 on architectures with thumb1

[PATCH][GCC][Arm] Missing optimization pattern for rev16 on architectures with thumb1

[Matthieu Longo]

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This patch marks a rev16 test as XFAIL for architectures having only 
Thumb1 support. The generated code is functionally correct, but the 
optimization is disabled when -mthumb is equivalent to Thumb1. Fixing 
the root issue would requires changes that are not suitable for GCC14 
stage 4.

More information at https://linaro.atlassian.net/browse/GNU-1141

gcc/testsuite/ChangeLog:

	* gcc.target/arm/rev16_2.c: XFAIL when compiled with Thumb1.

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From 11be6a0feb1cbc0bca6e23dacf98c5817b71ba3d Mon Sep 17 00:00:00 2001
From: Matthieu Longo <matthieu.longo@arm.com>
Date: Thu, 8 Feb 2024 18:13:49 +0000
Subject: [PATCH] [arm] Missing optimization pattern for rev16 on architectures
 with thumb1.

This patch marks a rev16 test as XFAIL for architectures having only Thumb1
support. The generated code is functionally correct, but the optimization is
disabled when -mthumb is equivalent to Thumb1. Fixing the root issue would
requires changes that are not suitable for GCC14 stage 4.
More information at https://linaro.atlassian.net/browse/GNU-1141

gcc/testsuite/ChangeLog:

	* gcc.target/arm/rev16_2.c: XFAIL when compiled with Thumb1.
---
 gcc/testsuite/gcc.target/arm/rev16_2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.target/arm/rev16_2.c b/gcc/testsuite/gcc.target/arm/rev16_2.c
index c6553b38a00..dff66e10bb9 100644
--- a/gcc/testsuite/gcc.target/arm/rev16_2.c
+++ b/gcc/testsuite/gcc.target/arm/rev16_2.c
@@ -17,4 +17,4 @@ __rev16_32 (__u32 x)
          | (((__u32)(x) & (__u32)0xff00ff00UL) >> 8);
 }
 
-/* { dg-final { scan-assembler-times {rev16\tr[0-9]+, r[0-9]+} 2 } } */
+/* { dg-final { scan-assembler-times {rev16\tr[0-9]+, r[0-9]+} 2 { xfail arm_thumb1_ok } } } */
\ No newline at end of file
-- 
2.34.1

Re: [PATCH][GCC][Arm] Missing optimization pattern for rev16 on architectures with thumb1

[Richard Earnshaw (lists)]

On 12/02/2024 13:48, Matthieu Longo wrote:
> This patch marks a rev16 test as XFAIL for architectures having only Thumb1 support. The generated code is functionally correct, but the optimization is disabled when -mthumb is equivalent to Thumb1. Fixing the root issue would requires changes that are not suitable for GCC14 stage 4.
> 
> More information at https://linaro.atlassian.net/browse/GNU-1141
> 
> gcc/testsuite/ChangeLog:
> 
>     * gcc.target/arm/rev16_2.c: XFAIL when compiled with Thumb1.

Thanks, I've tweaked the commit message slightly and pushed this.

R.