[gcc r14-9194] arm: warn about deprecation of iwmmx in mmintrin.h

[gcc r14-9194] arm: warn about deprecation of iwmmx in mmintrin.h

[Richard Earnshaw]

https://gcc.gnu.org/g:a82ecdeacf83996321de5312522b0cc961e02a95

commit r14-9194-ga82ecdeacf83996321de5312522b0cc961e02a95
Author: Richard Earnshaw <rearnsha@arm.com>
Date:   Mon Feb 26 17:20:58 2024 +0000

    arm: warn about deprecation of iwmmx in mmintrin.h
    
    GCC 13's changes file documents that iwmmx is deprecated.  Raise the bar
    by warning when the mmintrin.h header is included by users, but provide
    a way to suppress the warning.
    
    gcc:
            * config/arm/mmintrin.h: Warn if this header is included without
            defining __ENABLE_DEPRECATED_IWMMXT.

Diff:
---
 gcc/config/arm/mmintrin.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/config/arm/mmintrin.h b/gcc/config/arm/mmintrin.h
index 07659502bf2..e9cc3ddd7ab 100644
--- a/gcc/config/arm/mmintrin.h
+++ b/gcc/config/arm/mmintrin.h
@@ -28,6 +28,9 @@
 #error mmintrin.h included without enabling WMMX/WMMX2 instructions (e.g. -march=iwmmxt or -march=iwmmxt2)
 #endif
 
+#ifndef __ENABLE_DEPRECATED_IWMMXT
+#warning support for WMMX/WMMX2 is deprecated and will be removed in GCC 15.  Define __ENABLE_DEPRECATED_IWMMXT to suppress this warning
+#endif
 
 #if defined __cplusplus
 extern "C" {