https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120050
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords|needs-bisection |needs-reduction
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=116039
--- Comment #3 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
The first bad commit is r15-2321:
commit 34fb0feca71f763b2fbe832548749666d34a4a76
Author: Jeff Law <j...@ventanamicro.com>
Date: Thu Jul 25 12:32:28 2024 -0600
[PR rtl-optimization/116039] Fix life computation for promoted subregs
At this commit the bootstrap failure is different from GCC-15.1.0:
<quote>
build/genhooks -d \
../../gcc/gcc/doc/tm.texi.in > tmp-tm.texi
case `echo X|tr X '\101'` in \
A) tr -d '\015' < tmp-tm.texi > tmp2-tm.texi ;; \
*) tr -d '\r' < tmp-tm.texi > tmp2-tm.texi ;; \
esac
mv tmp2-tm.texi tmp-tm.texi
/bin/sh ../../gcc/gcc/../move-if-change tmp-tm.texi tm.texi
Verify that you have permission to grant a GFDL license for all
new text in /root/gcc15/build/gcc/tm.texi, then copy it to
../../gcc/gcc/doc/tm.texi.
</quote>
The (re)generated tm.texi has many additional empty lines comparing to the
original one, like:
--- ../gcc/gcc/doc/tm.texi 2025-05-02 11:16:01.182666959 +0800
+++ gcc/tm.texi 2025-05-02 20:54:36.763978130 +0800
@@ -408,6 +408,8 @@
@code{LINK_GCC_C_SEQUENCE_SPEC} instead.
@end defmac
+
+
@deftypevr {Common Target Hook} bool TARGET_ALWAYS_STRIP_DOTDOT
True if @file{..} components should always be removed from directory names
computed relative to GCC's internal directories, false (default) if such
@@ -678,6 +680,8 @@
any target-specific headers.
@end deftypevar
Thus it seems genhooks is miscompiled at -O3 -march=gs464. Maybe we need to
reduce a test case from genhooks...
I'd not try reverting PR116039 fix: as one reporter of its duplicates I know
it's a very serious issue. But maybe I can try bootstrapping with
-fno-ext-dce.
