[Mesa-dev] [PATCH] gallivm: disable avx512 features

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

We don't target this yet, and some llvm versions incorrectly enable it based
on cpu string, causing crashes.
(Albeit this is a losing battle, it is pretty much guaranteed when the next
new feature comes along llvm will mistakenly enable it on some future cpu,
thus we would have to proactively disable all new features as llvm adds them.)

This should fix https://bugs.freedesktop.org/show_bug.cgi?id=94291 (untested)

CC: <mesa-stable at lists.freedesktop.org>
---
 src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
index e47146a..af473a8 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
+++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
@@ -566,6 +566,18 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
    MAttrs.push_back(util_cpu_caps.has_avx  ? "+avx"  : "-avx");
    MAttrs.push_back(util_cpu_caps.has_f16c ? "+f16c" : "-f16c");
    MAttrs.push_back(util_cpu_caps.has_avx2 ? "+avx2" : "-avx2");
+   /* disable avx512 and all subvariants */
+#if HAVE_LLVM >= 0x0304
+   MAttrs.push_back("-avx512cd");
+   MAttrs.push_back("-avx512er");
+   MAttrs.push_back("-avx512f");
+   MAttrs.push_back("-avx512pf");
+#endif
+#if HAVE_LLVM >= 0x0305
+   MAttrs.push_back("-avx512bw");
+   MAttrs.push_back("-avx512dq");
+   MAttrs.push_back("-avx512vl");
+#endif
 #endif
 
 #if defined(PIPE_ARCH_PPC)
-- 
2.1.4