| Message ID | 20221026175430.3927965-1-thomas.petazzoni@bootlin.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | package/binutils: prevent selecting 2.37 for AVX512 systems | expand |
Thomas, All, On 2022-10-26 19:54 +0200, Thomas Petazzoni via buildroot spake thusly: > Support for the AVX512FP16 instructions was added in binutils > 2.38. See the binutils 2.38 releases notes [0] that state: > X86: > [...] > * Add support for Intel AVX512_FP16 instructions. [--SNIP--] > Also, in Buildroot, we do not distinguish AVX512 in general from > AVX512FP16 specifically, so our only option is to make binutils 2.37 > unavailable for AVX512 systems even if some of them perhaps don't > support AVX512FP16 anyway. This seems like a reasonable trade-off, as > binutils 2.38 is anyway already the default in Buildroot, and > AVX512-capable systems are fairly recent, and therefore using a recent > binutils version should not be a problem on these platforms. ACK > Fixes: > > http://autobuild.buildroot.net/results/eb6e28c934654e6d714973415a2fb452f9580279/ > > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Applied to master, thanks. Regards, Yann E. MORIN. > --- > package/binutils/Config.in.host | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/package/binutils/Config.in.host b/package/binutils/Config.in.host > index 51802db043..5dd2af2f9c 100644 > --- a/package/binutils/Config.in.host > +++ b/package/binutils/Config.in.host > @@ -14,6 +14,9 @@ choice > > config BR2_BINUTILS_VERSION_2_37_X > bool "binutils 2.37" > + # AVX512FP16 instructions were not supported before binutils > + # 2.38 > + depends on !BR2_X86_CPU_HAS_AVX512 > > config BR2_BINUTILS_VERSION_2_38_X > bool "binutils 2.38" > -- > 2.37.3 > > _______________________________________________ > buildroot mailing list > buildroot@buildroot.org > https://lists.buildroot.org/mailman/listinfo/buildroot
diff --git a/package/binutils/Config.in.host b/package/binutils/Config.in.host index 51802db043..5dd2af2f9c 100644 --- a/package/binutils/Config.in.host +++ b/package/binutils/Config.in.host @@ -14,6 +14,9 @@ choice config BR2_BINUTILS_VERSION_2_37_X bool "binutils 2.37" + # AVX512FP16 instructions were not supported before binutils + # 2.38 + depends on !BR2_X86_CPU_HAS_AVX512 config BR2_BINUTILS_VERSION_2_38_X bool "binutils 2.38"
Support for the AVX512FP16 instructions was added in binutils 2.38. See the binutils 2.38 releases notes [0] that state: X86: [...] * Add support for Intel AVX512_FP16 instructions. [0] https://sourceware.org/pipermail/binutils/2022-February/119721.html It turns out that when building GCC 12.x, some of these AVX512FP16 instructions are now used, and therefore when binutils < 2.38 is used, the build fails as the assembler does not recognize those instructions: /tmp/ccChzL2g.s: Assembler messages: /tmp/ccChzL2g.s:20: Error: no such instruction: `vmovw 24(%esp),%xmm2' /tmp/ccChzL2g.s:21: Error: no such instruction: `vmovw 28(%esp),%xmm3' /tmp/ccChzL2g.s:22: Error: no such instruction: `vmovw 32(%esp),%xmm4' /tmp/ccChzL2g.s:23: Error: no such instruction: `vmovw 36(%esp),%xmm5' /tmp/ccChzL2g.s:30: Error: no such instruction: `vcvtsh2ss %xmm2,%xmm6,%xmm6' /tmp/ccChzL2g.s:36: Error: no such instruction: `vcvtsh2ss %xmm3,%xmm6,%xmm6' /tmp/ccChzL2g.s:42: Error: no such instruction: `vcvtsh2ss %xmm4,%xmm7,%xmm7' /tmp/ccChzL2g.s:48: Error: no such instruction: `vcvtsh2ss %xmm5,%xmm1,%xmm1' /tmp/ccChzL2g.s:80: Error: no such instruction: `vcvtss2sh (%esp),%xmm1,%xmm1' /tmp/ccChzL2g.s:96: Error: no such instruction: `vcvtss2sh (%esp),%xmm0,%xmm0' /tmp/ccChzL2g.s:100: Error: no such instruction: `vucomish %xmm1,%xmm1' /tmp/ccChzL2g.s:103: Error: no such instruction: `vucomish %xmm0,%xmm0' /tmp/ccChzL2g.s:122: Error: no such instruction: `vucomish %xmm2,%xmm2' The same issue does not occur with GCC 11.x, but nothing prevents other packages than GCC to use those instructions, so the problem really lies on the binutils side missing the support for those instructions. Also, in Buildroot, we do not distinguish AVX512 in general from AVX512FP16 specifically, so our only option is to make binutils 2.37 unavailable for AVX512 systems even if some of them perhaps don't support AVX512FP16 anyway. This seems like a reasonable trade-off, as binutils 2.38 is anyway already the default in Buildroot, and AVX512-capable systems are fairly recent, and therefore using a recent binutils version should not be a problem on these platforms. Fixes: http://autobuild.buildroot.net/results/eb6e28c934654e6d714973415a2fb452f9580279/ Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> --- package/binutils/Config.in.host | 3 +++ 1 file changed, 3 insertions(+)