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[v2,9/9] aarch64: Handle alignment when it is bigger than BIGGEST_ALIGNMENT

Message ID DBBPR83MB0613871922DC43897016B3F8F89E2@DBBPR83MB0613.EURPRD83.prod.outlook.com
State New
Headers show
Series SMALL code model fixes, optimization fixes, LTO and minimal C++ enablement | expand

Commit Message

Evgeny Karpov Sept. 6, 2024, 12:04 p.m. UTC 
In some cases, the alignment can be bigger than BIGGEST_ALIGNMENT.

The issue was detected while building FFmpeg.
It creates structures, most likely for AVX optimization.

For instance:
float __attribute__((aligned (32))) large_aligned_array[3];

BIGGEST_ALIGNMENT could be up to 512 bits on x64.
This patch has been added to cover this case without needing to
change the FFmpeg code.

gcc/ChangeLog:

	* config/aarch64/aarch64-coff.h (ASM_OUTPUT_ALIGNED_LOCAL):
	Change alignment.
---
 gcc/config/aarch64/aarch64-coff.h | 10 ++++++++++
 1 file changed, 10 insertions(+)
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Patch

diff --git a/gcc/config/aarch64/aarch64-coff.h b/gcc/config/aarch64/aarch64-coff.h
index 17f346fe540..bf8e30b9c08 100644
--- a/gcc/config/aarch64/aarch64-coff.h
+++ b/gcc/config/aarch64/aarch64-coff.h
@@ -58,6 +58,16 @@ 
   assemble_name ((FILE), (NAME)),		\
   fprintf ((FILE), ",%lu\n", (ROUNDED)))
 
+#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGNMENT)  \
+  { \
+    unsigned HOST_WIDE_INT rounded = MAX ((SIZE), 1); \
+    unsigned HOST_WIDE_INT alignment = MAX ((ALIGNMENT), BIGGEST_ALIGNMENT); \
+    rounded += (alignment / BITS_PER_UNIT) - 1; \
+    rounded = (rounded / (alignment / BITS_PER_UNIT) \
+      * (alignment / BITS_PER_UNIT)); \
+    ASM_OUTPUT_LOCAL (FILE, NAME, SIZE, rounded); \
+  }
+
 #define ASM_OUTPUT_SKIP(STREAM, NBYTES) 	\
   fprintf (STREAM, "\t.space\t%d  // skip\n", (int) (NBYTES))