https://gcc.gnu.org/g:098cf067772921764e7eb618e3e0614a7df0a947
commit r16-3431-g098cf067772921764e7eb618e3e0614a7df0a947
Author: Tobias Burnus <tbur...@baylibre.com>
Date: Thu Aug 28 10:52:01 2025 +0200
[gcn] gcc/configure.ac + install.texi - changes to detect HAVE_AS_LEB128
[PR119367]
The llvm-mc linker by default assemblies to another assembly file and not
to an ELF
binary; that usually does not matter – but for the LEB128 check,
additionally, the
resulting binary is checked. Hence, when using llvm-mc as target linker for
amdgcn-*-*, we better add the "--filetype=obj -triple=amdgcn--amdhsa"
flags. The
current patch does so unconditionally, assuming that always llvm-mc is used.
Additionally, the resulting ELF file is checked, which requires an ELF
reader such
as objdump. This commit adds llvm-objdump to the build documentation for
amdgcn,
albeit also, e.g., Binutil's 'objdump' would do - as long as either
amdgcn-amdhsa-objdump or amdgcn-amdhsa/bin/objdump is found during the
amdgcn
cross build.
gcc/ChangeLog:
PR debug/119367
* acinclude.m4 (gcc_GAS_FLAGS): For gcn, use "--filetype=obj
-triple=amdgcn--amdhsa", if supported.
* configure: Regenerate.
* doc/install.texi (amdgcn-*-*): Also add llvm-objdump to the list
of
to-be-copied files.
Diff:
---
gcc/acinclude.m4 | 5 +++++
gcc/configure | 3 +++
gcc/doc/install.texi | 1 +
3 files changed, 9 insertions(+)
diff --git a/gcc/acinclude.m4 b/gcc/acinclude.m4
index ca4820221d57..764c7d1e8479 100644
--- a/gcc/acinclude.m4
+++ b/gcc/acinclude.m4
@@ -481,6 +481,11 @@ AC_DEFUN([gcc_GAS_FLAGS],
dnl Always pass -arch ppc to assembler.
gcc_cv_as_flags="-arch ppc"
;;
+ amdgcn*)
+ dnl Currently, only the llvm-mc assembler is supported.
+ dnl Add flags to ensure an amdgcn ELF file is written.
+ gcc_cv_as_flags="--filetype=obj -triple=amdgcn--amdhsa"
+ ;;
*)
gcc_cv_as_flags=" "
;;
diff --git a/gcc/configure b/gcc/configure
index 013865a2bb63..8aff04fa2936 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -25638,6 +25638,9 @@ else
powerpc*-*-darwin*)
gcc_cv_as_flags="-arch ppc"
;;
+ amdgcn*)
+ gcc_cv_as_flags="--filetype=obj -triple=amdgcn--amdhsa"
+ ;;
*)
gcc_cv_as_flags=" "
;;
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 6913035b5966..f2a8d0e24abe 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -4065,6 +4065,7 @@ AMD GCN GPU target.
Instead of GNU Binutils, you need to install LLVM and copy
@file{bin/llvm-mc} to @file{amdgcn-amdhsa/bin/as},
@file{bin/lld} to @file{amdgcn-amdhsa/bin/ld},
+@file{bin/llvm-objdump} to @file{amdgcn-amdhsa/bin/objdump},
@file{bin/llvm-nm} to @file{amdgcn-amdhsa/bin/nm}, and
@file{bin/llvm-ar} to both @file{bin/amdgcn-amdhsa-ar} and
@file{bin/amdgcn-amdhsa-ranlib}.
