Hi
Am 02.04.25 um 12:44 schrieb Matthew Auld:
Build fails with:
error: multiple unsequenced modifications to 'sbuf32'
[-Werror,-Wunsequenced]
264 | le32_to_cpup(sbuf32++),
| ^
265 | le32_to_cpup(sbuf32++),
| ~~
With that move the increment of the sbuf32 pointer to the end of the
loop, instead of inside the array list initializer, where the
order/sequence of the sbuf32 pointer modifications is not defined.
Fixes: 58523a25cbf7 ("drm/format-helper: Optimize 32-to-24-bpp conversion")
Fixes: 3f31a017ddbc ("drm/format-helper: Optimize 32-to-16-bpp conversion")
Fixes: 65931bbc5177 ("drm/format-helper: Optimize 32-to-8-bpp conversion")
Signed-off-by: Matthew Auld <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Jocelyn Falempe <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Thanks for the fix. I build with W=1 but never saw this error. Do you
use other build flags?
Best regards
Thomas
---
drivers/gpu/drm/drm_format_helper.c | 32 ++++++++++++++++-------------
1 file changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/drm_format_helper.c
b/drivers/gpu/drm/drm_format_helper.c
index fc7347caf600..d36e6cacc575 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -261,10 +261,10 @@ static __always_inline void drm_fb_xfrm_line_32to8(void
*dbuf, const void *sbuf,
/* write 4 pixels at once */
while (sbuf32 < ALIGN_DOWN_PIXELS(send32, pixels, 4)) {
u32 pix[4] = {
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
+ le32_to_cpup(sbuf32),
+ le32_to_cpup(sbuf32 + 1),
+ le32_to_cpup(sbuf32 + 2),
+ le32_to_cpup(sbuf32 + 3),
};
/* write output bytes in reverse order for little endianness */
u32 val32 = xfrm_pixel(pix[0]) |
@@ -272,6 +272,7 @@ static __always_inline void drm_fb_xfrm_line_32to8(void
*dbuf, const void *sbuf,
(xfrm_pixel(pix[2]) << 16) |
(xfrm_pixel(pix[3]) << 24);
*dbuf32++ = cpu_to_le32(val32);
+ sbuf32 += ARRAY_SIZE(pix);
}
/* write trailing pixels */
@@ -294,10 +295,10 @@ static __always_inline void drm_fb_xfrm_line_32to16(void
*dbuf, const void *sbuf
/* write 4 pixels at once */
while (sbuf32 < ALIGN_DOWN_PIXELS(send32, pixels, 4)) {
u32 pix[4] = {
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
+ le32_to_cpup(sbuf32),
+ le32_to_cpup(sbuf32 + 1),
+ le32_to_cpup(sbuf32 + 2),
+ le32_to_cpup(sbuf32 + 3),
};
/* write output bytes in reverse order for little endianness */
u64 val64 = ((u64)xfrm_pixel(pix[0])) |
@@ -305,6 +306,7 @@ static __always_inline void drm_fb_xfrm_line_32to16(void
*dbuf, const void *sbuf
((u64)xfrm_pixel(pix[2]) << 32) |
((u64)xfrm_pixel(pix[3]) << 48);
*dbuf64++ = cpu_to_le64(val64);
+ sbuf32 += ARRAY_SIZE(pix);
}
#endif
@@ -312,13 +314,14 @@ static __always_inline void drm_fb_xfrm_line_32to16(void *dbuf, const void *sbuf
dbuf32 = (__le32 __force *)dbuf64;
while (sbuf32 < ALIGN_DOWN_PIXELS(send32, pixels, 2)) {
u32 pix[2] = {
- le32_to_cpup(sbuf32++),
- le32_to_cpup(sbuf32++),
+ le32_to_cpup(sbuf32),
+ le32_to_cpup(sbuf32 + 1),
};
/* write output bytes in reverse order for little endianness */
u32 val32 = xfrm_pixel(pix[0]) |
(xfrm_pixel(pix[1]) << 16);
*dbuf32++ = cpu_to_le32(val32);
+ sbuf32 += ARRAY_SIZE(pix);
}
/* write trailing pixel */
@@ -339,10 +342,10 @@ static __always_inline void drm_fb_xfrm_line_32to24(void
*dbuf, const void *sbuf
/* write pixels in chunks of 4 */
while (sbuf32 < ALIGN_DOWN_PIXELS(send32, pixels, 4)) {
u32 val24[4] = {
- xfrm_pixel(le32_to_cpup(sbuf32++)),
- xfrm_pixel(le32_to_cpup(sbuf32++)),
- xfrm_pixel(le32_to_cpup(sbuf32++)),
- xfrm_pixel(le32_to_cpup(sbuf32++)),
+ xfrm_pixel(le32_to_cpup(sbuf32)),
+ xfrm_pixel(le32_to_cpup(sbuf32 + 1)),
+ xfrm_pixel(le32_to_cpup(sbuf32 + 2)),
+ xfrm_pixel(le32_to_cpup(sbuf32 + 3)),
};
u32 out32[3] = {
/* write output bytes in reverse order for little
endianness */
@@ -363,6 +366,7 @@ static __always_inline void drm_fb_xfrm_line_32to24(void
*dbuf, const void *sbuf
*dbuf32++ = cpu_to_le32(out32[0]);
*dbuf32++ = cpu_to_le32(out32[1]);
*dbuf32++ = cpu_to_le32(out32[2]);
+ sbuf32 += ARRAY_SIZE(val24);
}
/* write trailing pixel */
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
