[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 Xi Ruoyao changed: What|Removed |Added Target Milestone|13.0|12.2 --- Comment #14 from Xi Ruoyao --- Though the bootstrap failure is a 13 regression, the code generation issue has been already haunting 12.1. It also breaks building GCC 13 on a system with GCC 12.1 and --disable-bootstrap. Change target milestone to 12.2 so it will show up on list of PRs fixed in 12.2.
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 Xi Ruoyao changed: What|Removed |Added Resolution|--- |FIXED Status|UNCONFIRMED |RESOLVED --- Comment #13 from Xi Ruoyao --- Fixed for trunk and gcc-12.
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #11 from CVS Commits --- The master branch has been updated by Xi Ruoyao : https://gcc.gnu.org/g:020b7d98589bbc928b5a66b1ed56b42af8791355 commit r13-1319-g020b7d98589bbc928b5a66b1ed56b42af8791355 Author: Xi Ruoyao Date: Tue Jun 28 16:00:14 2022 +0800 loongarch: exclude LARCH_PROLOGUE_TEMP from SIBCALL_REGS [PR 106096] The epilogue may clobber LARCH_PROLOGUE_TEMP ($r13/$t1), so it cannot be used for sibcalls. gcc/ChangeLog: PR target/106096 * config/loongarch/loongarch.h (REG_CLASS_CONTENTS): Exclude $r13 from SIBCALL_REGS. * config/loongarch/loongarch.cc (loongarch_regno_to_class): Change $r13 to JIRL_REGS. gcc/testsuite/ChangeLog: PR target/106096 * g++.target/loongarch/loongarch.exp: New test support file. * g++.target/loongarch/pr106096.C: New test.
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #12 from CVS Commits --- The releases/gcc-12 branch has been updated by Xi Ruoyao : https://gcc.gnu.org/g:8e230a3c02641792d87252bff7f7554e46da2c25 commit r12-8520-g8e230a3c02641792d87252bff7f7554e46da2c25 Author: Xi Ruoyao Date: Tue Jun 28 16:00:14 2022 +0800 loongarch: exclude LARCH_PROLOGUE_TEMP from SIBCALL_REGS [PR 106096] The epilogue may clobber LARCH_PROLOGUE_TEMP ($r13/$t1), so it cannot be used for sibcalls. gcc/ChangeLog: PR target/106096 * config/loongarch/loongarch.h (REG_CLASS_CONTENTS): Exclude $r13 from SIBCALL_REGS. * config/loongarch/loongarch.cc (loongarch_regno_to_class): Change $r13 to JIRL_REGS. gcc/testsuite/ChangeLog: PR target/106096 * g++.target/loongarch/loongarch.exp: New test support file. * g++.target/loongarch/pr106096.C: New test. (cherry picked from commit 020b7d98589bbc928b5a66b1ed56b42af8791355)
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #10 from chenglulu --- (In reply to Xi Ruoyao from comment #9) > Created attachment 53214 [details] > patch removing r13 from SIBCALL_REGS > > I'm testing this patch now. > > I suggest to apply this for trunk and gcc-12 branch first (as gcc-12 also > miscompiles the test case). > > Then if the reordering of RA preference can improve performance, you may > apply it later (and also adjust the changes in this patch again). OK!
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #9 from Xi Ruoyao --- Created attachment 53214 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53214=edit patch removing r13 from SIBCALL_REGS I'm testing this patch now. I suggest to apply this for trunk and gcc-12 branch first (as gcc-12 also miscompiles the test case). Then if the reordering of RA preference can improve performance, you may apply it later (and also adjust the changes in this patch again).
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096
--- Comment #8 from chenglulu ---
(In reply to Xi Ruoyao from comment #6)
> (In reply to chenglulu from comment #5)
> > Created attachment 53213 [details]
> > Modify the allocation order of caller saved registers.
>
> I think we need to completely prevent LARCH_PROLOGUE_TEMP from being used
> for sibcall:
>
> diff --git a/gcc/config/loongarch/loongarch.h
> b/gcc/config/loongarch/loongarch.h
> index 4d107a42209..f9de9a6e4fb 100644
> --- a/gcc/config/loongarch/loongarch.h
> +++ b/gcc/config/loongarch/loongarch.h
> @@ -511,7 +511,7 @@ enum reg_class
> #define REG_CLASS_CONTENTS \
> { \
>{ 0x, 0x, 0x }, /* NO_REGS */ \
> - { 0x001ff000, 0x, 0x }, /* SIBCALL_REGS */ \
> + { 0x001fd000, 0x, 0x }, /* SIBCALL_REGS */ \
>{ 0xff90, 0x, 0x }, /* JIRL_REGS */\
>{ 0xfffc, 0x, 0x }, /* CSR_REGS */ \
>{ 0x, 0x, 0x }, /* GR_REGS */ \
>
> Or even if LARCH_PROLOGUE_TEMP is less preferred, the register allocator may
> still use it for sibcall and blow something up again.
>
This solved my doubt. ^v^
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #7 from Xi Ruoyao --- (In reply to Xi Ruoyao from comment #6) > (In reply to chenglulu from comment #5) > > Created attachment 53213 [details] > > Modify the allocation order of caller saved registers. > > I think we need to completely prevent LARCH_PROLOGUE_TEMP from being used > for sibcall For example, the RISC-V change explicitly exclude x5 (their temp for epilogue): https://gcc.gnu.org/legacy-ml/gcc-patches/2019-10/msg01228.html
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096
--- Comment #6 from Xi Ruoyao ---
(In reply to chenglulu from comment #5)
> Created attachment 53213 [details]
> Modify the allocation order of caller saved registers.
I think we need to completely prevent LARCH_PROLOGUE_TEMP from being used for
sibcall:
diff --git a/gcc/config/loongarch/loongarch.h
b/gcc/config/loongarch/loongarch.h
index 4d107a42209..f9de9a6e4fb 100644
--- a/gcc/config/loongarch/loongarch.h
+++ b/gcc/config/loongarch/loongarch.h
@@ -511,7 +511,7 @@ enum reg_class
#define REG_CLASS_CONTENTS \
{ \
{ 0x, 0x, 0x }, /* NO_REGS */ \
- { 0x001ff000, 0x, 0x }, /* SIBCALL_REGS */ \
+ { 0x001fd000, 0x, 0x }, /* SIBCALL_REGS */ \
{ 0xff90, 0x, 0x }, /* JIRL_REGS */\
{ 0xfffc, 0x, 0x }, /* CSR_REGS */ \
{ 0x, 0x, 0x }, /* GR_REGS */ \
Or even if LARCH_PROLOGUE_TEMP is less preferred, the register allocator may
still use it for sibcall and blow something up again.
(Above is for $r13, if you want to use $r12 instead as LARCH_PROLOGUE_TEMP you
need to adjust it.)
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 --- Comment #5 from chenglulu --- Created attachment 53213 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53213=edit Modify the allocation order of caller saved registers.
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 Richard Biener changed: What|Removed |Added Target Milestone|--- |13.0
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 Xi Ruoyao changed: What|Removed |Added Known to work|12.1.0 | --- Comment #4 from Xi Ruoyao --- Remove "known to work" because 12.1.0 miscompiles the test case too.
[Bug target/106096] [13 regression] ICE building stage 2 libgcc on loongarch64-linux-gnu because stage 2 gcc is miscompiled
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106096 Xi Ruoyao changed: What|Removed |Added Build|loongarch64-linux-gnu | Summary|[13 regression] ICE |[13 regression] ICE |building stage 2 libgcc on |building stage 2 libgcc on |loongarch64-linux-gnu since |loongarch64-linux-gnu |r13-911 |because stage 2 gcc is ||miscompiled Host|loongarch64-linux-gnu | --- Comment #3 from Xi Ruoyao --- (In reply to Xi Ruoyao from comment #2) > Created attachment 53208 [details] > reduced testcase For this testcase GCC generates: .L20: lu12i.w $r13,4096>>12 # 0x1000 add.d $r3,$r3,$r13 ld.d$r1,$r3,24 or $r4,$r23,$r0 ld.d$r23,$r3,16 la.local$r5,b addi.d $r3,$r3,32 jr $r13
