Re: [committed] amdgcn: Remove LLVM 9 assembler/linker support

[Andrew Stubbs <ams@codesourcery.com>]

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On 27/05/2022 20:16, Thomas Schwinge wrote:
> Hi Andrew!
> 
> On 2022-05-24T16:27:52+0100, Andrew Stubbs <ams@codesourcery.com> wrote:
>> I've committed this patch to set the minimum required LLVM version, for
>> the assembler and linker, to 13.0.1. An upgrade from LLVM 9 is a
>> prerequisite for the gfx90a support, and 13.0.1 is now the oldest
>> version not known to have compatibility issues.
>>
>> The patch removes all the obsolete feature detection tests from
>> configure and adds a new version test. Likewise the version dependencies
>> in the backend are removed.
> 
> I've not otherwise reviewed your
> commit r13-742-g8086230e7ac619c0b0eeb6e15df7975ac214725f
> "amdgcn: Remove LLVM 9 assembler/linker support", but happened to notice
> that your commit also removed the ARM-target 'HAVE_GAS_ARM_EXTENDED_ARCH'
> -- is that intentional; I suppose not?  That had been added by Richard
> Earnshaw in commit r12-3725-g4e7a92c0ff3871d955ca8fb133f869b216d7224d
> "arm: pass architecture extensions to assembler if supported".

Ooops, this was not intentional. I've just committed the attached to 
reinstate it.

Richard, please confirm that it works as intended.

The problem was that the ARM test was inserted into a case statement 
that I created solely for the use of amdgcn. When I then removed that 
block of code I didn't notice the additional, unrelated code hiding in 
there.

Apologies for the inconvenience.

Andrew

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arm: reinstate HAVE_GAS_ARM_EXTENDED_ARCH

The check was removed by accident.

gcc/ChangeLog:

	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Reinstate HAVE_GAS_ARM_EXTENDED_ARCH test.

diff --git a/gcc/config.in b/gcc/config.in
index 6a4f8856c4f..16bb963b45b 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -1331,6 +1331,13 @@
 #endif
 
 
+/* Define if your Arm assembler permits context-specific feature extensions.
+   */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GAS_ARM_EXTENDED_ARCH
+#endif
+
+
 /* Define if your assembler supports .balign and .p2align. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_GAS_BALIGN_AND_P2ALIGN
diff --git a/gcc/configure b/gcc/configure
index 095065ed01a..a52574d02b5 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -731,10 +731,10 @@ gcc_cv_dsymutil
 gcc_cv_otool
 gcc_cv_readelf
 gcc_cv_objdump
-ORIGINAL_NM_FOR_TARGET
-gcc_cv_nm
 ORIGINAL_OBJCOPY_FOR_TARGET
 gcc_cv_objcopy
+ORIGINAL_NM_FOR_TARGET
+gcc_cv_nm
 ORIGINAL_LD_GOLD_FOR_TARGET
 ORIGINAL_LD_BFD_FOR_TARGET
 ORIGINAL_LD_FOR_TARGET
@@ -19676,7 +19676,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19676 "configure"
+#line 19679 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -19782,7 +19782,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19782 "configure"
+#line 19785 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -29118,6 +29118,44 @@ $as_echo "$gcc_cv_as_version, ok" >&6; }
     ;;
 esac
 
+case "$target" in
+  arm*)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for assembler for arm accepts context-specific architecture extensions" >&5
+$as_echo_n "checking assembler for assembler for arm accepts context-specific architecture extensions... " >&6; }
+if ${gcc_cv_as_arm_option_extensions+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_arm_option_extensions=no
+  if test x$gcc_cv_as != x; then
+    $as_echo '.text
+	.thumb
+	.syntax unified
+	vmov.f32 s0, s1' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags -march=armv8.1-m.main+mve -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_arm_option_extensions=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_arm_option_extensions" >&5
+$as_echo "$gcc_cv_as_arm_option_extensions" >&6; }
+if test $gcc_cv_as_arm_option_extensions = yes; then
+
+$as_echo "#define HAVE_GAS_ARM_EXTENDED_ARCH 1" >>confdefs.h
+
+fi
+
+esac
+
 # ??? Not all targets support dwarf2 debug_line, even within a version
 # of gas.  Moreover, we need to emit a valid instruction to trigger any
 # info to the output file.  So, as supported targets are added to gas 2.11,
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e098b905622..5fe826aa4eb 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -5427,6 +5427,19 @@ case "$target" in
     ;;
 esac
 
+case "$target" in
+  arm*)
+    gcc_GAS_CHECK_FEATURE([assembler for arm accepts context-specific architecture extensions],
+      gcc_cv_as_arm_option_extensions,
+      [-march=armv8.1-m.main+mve],
+      [.text
+	.thumb
+	.syntax unified
+	vmov.f32 s0, s1],,
+      [AC_DEFINE(HAVE_GAS_ARM_EXTENDED_ARCH, 1,
+       [Define if your Arm assembler permits context-specific feature extensions.])])
+esac
+
 # ??? Not all targets support dwarf2 debug_line, even within a version
 # of gas.  Moreover, we need to emit a valid instruction to trigger any
 # info to the output file.  So, as supported targets are added to gas 2.11,