On Fri, 21 Aug 2026 00:22:42 PDT (-0700), Kito Cheng wrote:
This seems more like a patch for riscv-gnu-toolchain rather than GCC?
Ya, I agree this is basically just a distro problem: if you're building
binaries you need to know what's implemented on the systems you're going
to be running them on.
That said: we did change the default behavior here so it's going to
break some users. We also don't have a great way to fix that, as we're
not doing ISA-based dynamic multilib resolution. So if I understand how
this all works, we've basically changed the default multilib to include
V when it didn't on older releases.
We've talked about trying to fix this ISA-dependent multilib resolution
stuff a few times. Last round we sort of got hung up on the "what
should the supported set of multilibs actually be", and I suspect we'd
end up there again (and likely will continue to end up there until
someone makes hardware that's actually interesting in these
binary-compatible use cases).
panciyan <[email protected]> 於 2026年8月19日週三 下午1:48寫道：
Building glibc with -march=rv64gcv causes GCC to auto-vectorize generic
C code (e.g. calc_state_hash in regex), generating RVV instructions. On
hardware without the V extension, this results in SIGILL.
Signed-off-by: Ciyan Pan <[email protected]>
ChangeLog:
* configure: Regenerate.
* configure.ac: Remove rv64gcv-lp64d.
---
configure | 5 -----
configure.ac | 2 +-
2 files changed, 1 insertion(+), 6 deletions(-)
diff --git a/configure b/configure
index d610aa16..6328fcee 100755
--- a/configure
+++ b/configure
@@ -4159,11 +4159,6 @@ fi
if test "x$enable_multilib" = xyes
then :
glibc_multilib_names="rv32imac-ilp32 rv32gc-ilp32d rv64imac-lp64
rv64gc-lp64d"
- # Vector extension is currently not supported on Big-endian systems.
- if test "x$endian" = xlittle
- then :
- glibc_multilib_names+=" rv64gcv-lp64d"
- fi
else $as_nop
glibc_multilib_names="$with_arch-$with_abi"
diff --git a/configure.ac b/configure.ac
index 4e534faa..dd32ec6c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -158,7 +158,7 @@ AS_IF([test "x$enable_multilib" = xyes || test
"x$with_multilib_generator" != xn
[AC_SUBST(multilib_flags,--disable-multilib)])
AS_IF([test "x$enable_multilib" = xyes],
- [AC_SUBST(glibc_multilib_names,"rv32imac-ilp32 rv32gc-ilp32d rv64imac-lp64
rv64gc-lp64d rv64gcv-lp64d")],
+ [AC_SUBST(glibc_multilib_names,"rv32imac-ilp32 rv32gc-ilp32d rv64imac-lp64
rv64gc-lp64d")],
[AC_SUBST(glibc_multilib_names,"$with_arch-$with_abi")])
AS_IF([test "x$enable_multilib" = xyes],
--
2.43.0
