diff mbox series

mesa: fix clang+lld link failure in addrlib AVX2 detection

Message ID 20260817182201.2388973-1-khem.raj@oss.qualcomm.com
State New
Headers show
Series mesa: fix clang+lld link failure in addrlib AVX2 detection | expand

Commit Message

Khem Raj Aug. 17, 2026, 6:22 p.m. UTC 
Fixes

ld.lld: error: relocation R_X86_64_PC32 cannot be used against
symbol '__cpu_model'; recompile with -fPIC

Check CPUID directly instead, avoiding the __cpu_model reference
entirely.

Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>
---
 ...uiltin_cpu_supports-for-avx2-detecti.patch | 56 +++++++++++++++++++
 meta/recipes-graphics/mesa/mesa.inc           |  1 +
 2 files changed, 57 insertions(+)
 create mode 100644 meta/recipes-graphics/mesa/files/0001-addrlib-avoid-builtin_cpu_supports-for-avx2-detecti.patch
diff mbox series

Patch

diff --git a/meta/recipes-graphics/mesa/files/0001-addrlib-avoid-builtin_cpu_supports-for-avx2-detecti.patch b/meta/recipes-graphics/mesa/files/0001-addrlib-avoid-builtin_cpu_supports-for-avx2-detecti.patch
new file mode 100644
index 0000000000..7234f76b39
--- /dev/null
+++ b/meta/recipes-graphics/mesa/files/0001-addrlib-avoid-builtin_cpu_supports-for-avx2-detecti.patch
@@ -0,0 +1,56 @@ 
+From: Khem Raj <khem.raj@oss.qualcomm.com>
+Date: Thu, 13 Aug 2026 00:00:00 +0000
+Subject: [PATCH] addrlib: avoid __builtin_cpu_supports for avx2 detection
+
+__builtin_cpu_supports("avx2") lowers to a PC-relative reference to the
+libgcc/compiler-rt __cpu_model global. With clang+lld, linking that
+reference into a shared library fails because __cpu_model is treated as
+preemptible there:
+
+  relocation R_X86_64_PC32 cannot be used against symbol '__cpu_model';
+  recompile with -fPIC
+
+Check CPUID directly instead, which avoids the __cpu_model reference
+entirely and works with both GCC and Clang.
+
+Upstream-Status: Submitted [https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/43820]
+Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>
+---
+ src/amd/addrlib/src/core/addrswizzlersimd.h | 15 +++++++++++++--
+ 1 file changed, 13 insertions(+), 2 deletions(-)
+
+diff --git a/src/amd/addrlib/src/core/addrswizzlersimd.h b/src/amd/addrlib/src/core/addrswizzlersimd.h
+index fd53e40..ce30204 100644
+--- a/src/amd/addrlib/src/core/addrswizzlersimd.h
++++ b/src/amd/addrlib/src/core/addrswizzlersimd.h
+@@ -57,6 +57,8 @@
+ #if ADDR_HAS_AVX2
+ #if _MSC_VER
+ #include <Windows.h>
++#else
++#include <cpuid.h>
+ #endif
+ #include <immintrin.h>
+
+@@ -85,7 +87,18 @@ static inline bool CpuSupportsAvx2() {
+ #if _MSC_VER
+     return IsProcessorFeaturePresent(PF_AVX2_INSTRUCTIONS_AVAILABLE);
+ #elif defined(__GNUC__)
+-    return __builtin_cpu_supports("avx2");
++    // __builtin_cpu_supports() lowers to a PC-relative reference to the
++    // libgcc/compiler-rt __cpu_model global, which some clang+lld
++    // configurations reject when linking into a shared library (the
++    // symbol is treated as preemptible: "relocation R_X86_64_PC32 cannot
++    // be used against symbol '__cpu_model'"). Check CPUID directly instead.
++    unsigned int eax, ebx, ecx, edx;
++    if (__get_cpuid_max(0, nullptr) < 7)
++    {
++        return false;
++    }
++    __cpuid_count(7, 0, eax, ebx, ecx, edx);
++    return (ebx & bit_AVX2) != 0;
+ #else
+ #error "What platform is this?"
+ #endif
+--
+2.43.0
diff --git a/meta/recipes-graphics/mesa/mesa.inc b/meta/recipes-graphics/mesa/mesa.inc
index a139ebb176..8ee7db50ed 100644
--- a/meta/recipes-graphics/mesa/mesa.inc
+++ b/meta/recipes-graphics/mesa/mesa.inc
@@ -19,6 +19,7 @@  SRC_URI = "https://archive.mesa3d.org/mesa-${PV}.tar.xz \
            file://0001-freedreno-don-t-encode-build-path-into-binaries.patch \
            file://0001-src-intel-compiler-jay-jay_ir.h-do-not-used-typed-en.patch \
            file://0001-src-util-u_math.c-do-not-use-arm-fpu-instructions-if.patch \
+           file://0001-addrlib-avoid-builtin_cpu_supports-for-avx2-detecti.patch \
            "
 
 SRC_URI[sha256sum] = "efd4bb08cdb7c365a812cd4e6c9202ab55b2f22cdcd13c7d6c4f9647b799a4ef"