* [Buildroot] S390 Buildroot/gcc build issue
@ 2026-08-11 11:42 Thomas Petazzoni via buildroot
2026-08-12 9:11 ` Alexander Egorenkov
0 siblings, 1 reply; 5+ messages in thread
From: Thomas Petazzoni via buildroot @ 2026-08-11 11:42 UTC (permalink / raw)
To: Alexander Egorenkov; +Cc: buildroot
Alexander,
I am contacting you regarding a build issue I'm seeing with the S390
architecture in Buildroot.
With the following defconfig:
BR2_s390x=y
BR2_KERNEL_HEADERS_6_12=y
BR2_PACKAGE_GLIBC_KERNEL_COMPAT=y
BR2_BINUTILS_VERSION_2_46_X=y
BR2_BINUTILS_GPROFNG=y
BR2_GCC_VERSION_16_X=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_TOOLCHAIN_BUILDROOT_FORTRAN=y
BR2_GCC_ENABLE_OPENMP=y
BR2_PACKAGE_HOST_GDB=y
BR2_PACKAGE_HOST_GDB_TUI=y
BR2_PACKAGE_HOST_GDB_PYTHON3=y
BR2_GDB_VERSION_17=y
BR2_GNU_MIRROR="https://mirrors.kernel.org/gnu/"
BR2_PACKAGE_GDB=y
gcc 16.2.0 fails to build with:
../../../libgcc/config/s390/_dpd_sd_to_hf.c:27:25: error: decimal floating-point not supported for this target
27 | HFtype __dpd_truncsdhf (_Decimal32);
| ^~~~~~~~~~
../../../libgcc/config/s390/_dpd_sd_to_hf.c:31:16: error: decimal floating-point not supported for this target
31 | force_convert (_Decimal32 x)
| ^~~~~~~~~~
../../../libgcc/config/s390/_dpd_hf_to_td.c:34:1: error: decimal floating-point not supported for this target
34 | _Decimal128
| ^~~~~~~~~~~
../../../libgcc/config/s390/_dpd_sd_to_hf.c:35:18: error: decimal floating-point not supported for this target
35 | __dpd_truncsdhf (_Decimal32 x)
| ^~~~~~~~~~
I haven't checked whether this is new with gcc 16.x or not, and I'm
not familiar with floating point support on S390.
Are you familiar with this issue?
I see the same issue with gcc 16.1.0 in the autobuilders:
https://autobuild.buildroot.net/results/f88/f88565af0f653df831a7fa43d2507d167fdb9d36/build-end.log
But I don't seem to see any issue with gcc 15.x, so my guess is that
this is a new issue with gcc 16.x.
Any idea?
Thanks a lot!
Thomas
--
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Buildroot] S390 Buildroot/gcc build issue 2026-08-11 11:42 [Buildroot] S390 Buildroot/gcc build issue Thomas Petazzoni via buildroot @ 2026-08-12 9:11 ` Alexander Egorenkov 2026-08-12 9:28 ` Thomas Petazzoni via buildroot 0 siblings, 1 reply; 5+ messages in thread From: Alexander Egorenkov @ 2026-08-12 9:11 UTC (permalink / raw) To: Thomas Petazzoni; +Cc: buildroot Thomas Petazzoni <thomas.petazzoni@bootlin.com> writes: > Alexander, > > I am contacting you regarding a build issue I'm seeing with the S390 > architecture in Buildroot. > > With the following defconfig: > > BR2_s390x=y > BR2_KERNEL_HEADERS_6_12=y > BR2_PACKAGE_GLIBC_KERNEL_COMPAT=y > BR2_BINUTILS_VERSION_2_46_X=y > BR2_BINUTILS_GPROFNG=y > BR2_GCC_VERSION_16_X=y > BR2_TOOLCHAIN_BUILDROOT_CXX=y > BR2_TOOLCHAIN_BUILDROOT_FORTRAN=y > BR2_GCC_ENABLE_OPENMP=y > BR2_PACKAGE_HOST_GDB=y > BR2_PACKAGE_HOST_GDB_TUI=y > BR2_PACKAGE_HOST_GDB_PYTHON3=y > BR2_GDB_VERSION_17=y > BR2_GNU_MIRROR="https://mirrors.kernel.org/gnu/" > BR2_PACKAGE_GDB=y > > gcc 16.2.0 fails to build with: > > ../../../libgcc/config/s390/_dpd_sd_to_hf.c:27:25: error: decimal floating-point not supported for this target > 27 | HFtype __dpd_truncsdhf (_Decimal32); > | ^~~~~~~~~~ > ../../../libgcc/config/s390/_dpd_sd_to_hf.c:31:16: error: decimal floating-point not supported for this target > 31 | force_convert (_Decimal32 x) > | ^~~~~~~~~~ > ../../../libgcc/config/s390/_dpd_hf_to_td.c:34:1: error: decimal floating-point not supported for this target > 34 | _Decimal128 > | ^~~~~~~~~~~ > ../../../libgcc/config/s390/_dpd_sd_to_hf.c:35:18: error: decimal floating-point not supported for this target > 35 | __dpd_truncsdhf (_Decimal32 x) > | ^~~~~~~~~~ > > I haven't checked whether this is new with gcc 16.x or not, and I'm > not familiar with floating point support on S390. > > Are you familiar with this issue? > > I see the same issue with gcc 16.1.0 in the autobuilders: > > https://autobuild.buildroot.net/results/f88/f88565af0f653df831a7fa43d2507d167fdb9d36/build-end.log > > But I don't seem to see any issue with gcc 15.x, so my guess is that > this is a new issue with gcc 16.x. > Hi, the types _Decimal* require for the host compiler to be built with --enable-decimal-float. package/gcc/gcc.mk: ------------------- HOST_GCC_COMMON_CONF_OPTS = \ --target=$(GNU_TARGET_NAME) \ --with-sysroot=$(STAGING_DIR) \ --enable-__cxa_atexit \ --with-gnu-ld \ --disable-libssp \ --disable-multilib \ --disable-decimal-float <----- !!! Can we turn --disable-decimal-float into --enable-decimal-float on s390x arch ? It fixed the problem for me. package/gcc/gcc.mk: ------------------- ifeq ($(BR2_s390x),y) HOST_GCC_COMMON_CONF_OPTS += \ --with-long-double-128 \ --enable-decimal-float <----- !!! endif Regards Alex _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Buildroot] S390 Buildroot/gcc build issue 2026-08-12 9:11 ` Alexander Egorenkov @ 2026-08-12 9:28 ` Thomas Petazzoni via buildroot 2026-08-12 9:32 ` Alexander Egorenkov 2026-08-26 20:04 ` Thomas Petazzoni via buildroot 0 siblings, 2 replies; 5+ messages in thread From: Thomas Petazzoni via buildroot @ 2026-08-12 9:28 UTC (permalink / raw) To: Alexander Egorenkov; +Cc: buildroot Hello, On Wed, Aug 12, 2026 at 11:11:10AM +0200, Alexander Egorenkov wrote: > the types _Decimal* require for the host compiler to be built with > --enable-decimal-float. What do you call the "host compiler" in this context? Are you talking about the native gcc compiler available on the host, or the cross-compiler built by Buildroot? > > package/gcc/gcc.mk: > ------------------- > > HOST_GCC_COMMON_CONF_OPTS = \ > --target=$(GNU_TARGET_NAME) \ > --with-sysroot=$(STAGING_DIR) \ > --enable-__cxa_atexit \ > --with-gnu-ld \ > --disable-libssp \ > --disable-multilib \ > --disable-decimal-float <----- !!! These are the common options... > Can we turn --disable-decimal-float into --enable-decimal-float on > s390x arch ? It fixed the problem for me. > > package/gcc/gcc.mk: > ------------------- > > ifeq ($(BR2_s390x),y) > HOST_GCC_COMMON_CONF_OPTS += \ > --with-long-double-128 \ > --enable-decimal-float <----- !!! and for S390, it gets overridden. See: it's the same variable that gets appended, so at the end we have: HOST_GCC_COMMON_CONF_OPTS = \ [...] --disable-decimal-float \ [...] --enable-decimal-float So on S390, the cross-compiler is built with --enable-decimal-float. Best regards, Thomas -- Thomas Petazzoni, co-owner and CEO, Bootlin Embedded Linux and Kernel engineering and training https://bootlin.com _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Buildroot] S390 Buildroot/gcc build issue 2026-08-12 9:28 ` Thomas Petazzoni via buildroot @ 2026-08-12 9:32 ` Alexander Egorenkov 2026-08-26 20:04 ` Thomas Petazzoni via buildroot 1 sibling, 0 replies; 5+ messages in thread From: Alexander Egorenkov @ 2026-08-12 9:32 UTC (permalink / raw) To: Thomas Petazzoni; +Cc: buildroot Thomas Petazzoni <thomas.petazzoni@bootlin.com> writes: > Hello, > > On Wed, Aug 12, 2026 at 11:11:10AM +0200, Alexander Egorenkov wrote: > >> the types _Decimal* require for the host compiler to be built with >> --enable-decimal-float. > > What do you call the "host compiler" in this context? > > Are you talking about the native gcc compiler available on the host, > or the cross-compiler built by Buildroot? > A cross-compiler built by Buildroot. > and for S390, it gets overridden. > > See: it's the same variable that gets appended, so at the end we have: > > HOST_GCC_COMMON_CONF_OPTS = \ > [...] > --disable-decimal-float \ > [...] > --enable-decimal-float > > So on S390, the cross-compiler is built with --enable-decimal-float. Sorry for not being clear here, this was added by me for testing ;-) I this change is okay, then i'll send a patch. Not sure here, do we need to deal with Gcc 15 conditionally here ? Regards Alex _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Buildroot] S390 Buildroot/gcc build issue 2026-08-12 9:28 ` Thomas Petazzoni via buildroot 2026-08-12 9:32 ` Alexander Egorenkov @ 2026-08-26 20:04 ` Thomas Petazzoni via buildroot 1 sibling, 0 replies; 5+ messages in thread From: Thomas Petazzoni via buildroot @ 2026-08-26 20:04 UTC (permalink / raw) To: Alexander Egorenkov; +Cc: buildroot Hello Alexander, Do you have some updates about the S390 gcc build issues? (See below). Thanks a lot for your feedback, Thomas On Wed, Aug 12, 2026 at 11:29:02AM +0200, Thomas Petazzoni wrote: > Hello, > > On Wed, Aug 12, 2026 at 11:11:10AM +0200, Alexander Egorenkov wrote: > > > the types _Decimal* require for the host compiler to be built with > > --enable-decimal-float. > > What do you call the "host compiler" in this context? > > Are you talking about the native gcc compiler available on the host, > or the cross-compiler built by Buildroot? > > > > > package/gcc/gcc.mk: > > ------------------- > > > > HOST_GCC_COMMON_CONF_OPTS = \ > > --target=$(GNU_TARGET_NAME) \ > > --with-sysroot=$(STAGING_DIR) \ > > --enable-__cxa_atexit \ > > --with-gnu-ld \ > > --disable-libssp \ > > --disable-multilib \ > > --disable-decimal-float <----- !!! > > These are the common options... > > > Can we turn --disable-decimal-float into --enable-decimal-float on > > s390x arch ? It fixed the problem for me. > > > > package/gcc/gcc.mk: > > ------------------- > > > > ifeq ($(BR2_s390x),y) > > HOST_GCC_COMMON_CONF_OPTS += \ > > --with-long-double-128 \ > > --enable-decimal-float <----- !!! > > and for S390, it gets overridden. > > See: it's the same variable that gets appended, so at the end we have: > > HOST_GCC_COMMON_CONF_OPTS = \ > [...] > --disable-decimal-float \ > [...] > --enable-decimal-float > > So on S390, the cross-compiler is built with --enable-decimal-float. > > Best regards, > > Thomas > -- > Thomas Petazzoni, co-owner and CEO, Bootlin > Embedded Linux and Kernel engineering and training > https://bootlin.com -- Thomas Petazzoni, co-owner and CEO, Bootlin Embedded Linux and Kernel engineering and training https://bootlin.com _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-08-26 20:04 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-08-11 11:42 [Buildroot] S390 Buildroot/gcc build issue Thomas Petazzoni via buildroot 2026-08-12 9:11 ` Alexander Egorenkov 2026-08-12 9:28 ` Thomas Petazzoni via buildroot 2026-08-12 9:32 ` Alexander Egorenkov 2026-08-26 20:04 ` Thomas Petazzoni via buildroot
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