https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116625
Bug ID: 116625
Summary: [15 regression] regressions on arm-eabi since
r15-1619-g3b9b8d6cfdf593
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: testsuite-fail
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: thiago.bauermann at linaro dot org
CC: jskumari at gcc dot gnu.org
Target Milestone: ---
Target: arm
Created attachment 59056
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59056&action=edit
diff of all generated assembly files
Since commit r15-1619-g3b9b8d6cfdf593 we see on arm-eabi all the regressions
reported in bug 116623, plus the ones below:
Running gcc:gcc.target/arm/cmse/cmse.exp ...
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-4.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-4.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-4.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-4.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-6.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-6.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-6.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-6.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-8.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-8.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-8.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-8.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O1 scan-assembler
lsls\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O1 scan-assembler
lsrs\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O2 scan-assembler
lsls\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O2 scan-assembler
lsrs\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O3 -g scan-assembler
lsls\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/bitfield-and-union.c
-march=armv8.1-m.main+fp -mthumb -O3 -g scan-assembler
lsrs\t(r[4-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/union-2.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/union-2.c -march=armv8.1-m.main+fp
-mthumb -O2 scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/union-2.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsls\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
FAIL: gcc.target/arm/cmse/mainline/8_1m/union-2.c -march=armv8.1-m.main+fp
-mthumb -O3 -g scan-assembler lsrs\t(r[3-9]|r10|fp|ip), \\1, #1.*blxns\t\\1
In all of the failures above, the problem is that GCC is now using lsr/lsl
instructions rather than lsrs/lsls. For example:
diff -u '--color=auto' -pruN before/bitfield-4-O2.s after/bitfield-4-O2.s
--- before/bitfield-4-O2.s 2024-09-06 00:14:05.084343596 -0300
+++ after/bitfield-4-O2.s 2024-09-05 23:44:18.400186871 -0300
@@ -29,14 +29,14 @@ main:
mov r0, #-1
mov r1, #-1
mov r2, #-1
- push {r4, lr}
- sub sp, sp, #16
+ push {lr}
+ sub sp, sp, #20
strd r0, [sp]
str r2, [sp, #8]
ldm sp, {r0, r1, r2}
- mov r4, #2097152
- lsrs r4, r4, #1
- lsls r4, r4, #1
+ mov ip, #2097152
+ lsr ip, ip, #1
+ lsl ip, ip, #1
push {r4, r5, r6, r7, r8, r9, r10, fp}
vpush.64 {d8, d9, d10, d11, d12, d13, d14, d15}
movw ip, #65535
I'm attaching the diff of all generated assembly files.
These are the configure options used:
/tmp/combined-tree-src/configure \
SHELL=/bin/bash \
--with-gnu-as \
--with-gnu-ld \
--enable-lto \
--enable-shared \
--without-included-gettext \
--enable-nls \
--with-system-zlib \
--disable-sjlj-exceptions \
--enable-gnu-unique-object \
--enable-linker-build-id \
--disable-libstdcxx-pch \
--enable-c99 \
--enable-clocale=gnu \
--enable-libstdcxx-debug \
--enable-long-long \
--with-isl=no \
--enable-threads=no \
--disable-multiarch \
--disable-multilib \
--with-mode=thumb \
--with-arch=armv8.1-m.main+mve.fp+fp.dp \
--with-float=hard \
--with-headers=yes \
--with-native-system-header-dir=/include \
--with-newlib \
--enable-checking=yes \
--disable-bootstrap \
--disable-gdb \
--enable-languages=c,c++,lto \
--prefix=/tmp/thumb-m55-hard-eabi \
--build=x86_64-pc-linux-gnu \
--host=x86_64-pc-linux-gnu \
--target=arm-eabi
