x86: add comments about the binutils version to support code in as-instr

We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b3 ("kbuild: Raise the minimum required binutils version to 2.21"). We have these as-instr tests because binutils 2.21 does not support them. When we bump the binutils version next time, this will be a good hint to find out which one can be dropped. As for the Clang/LLVM builds, we require very new LLVM version, so the LLVM integrated assembler supports all of them. Signed-off-by: Masahiro Yamada <[email protected]> Acked-by: Jason A. Donenfeld <[email protected]> Acked-by: Ingo Molnar <[email protected]> Acked-by: Nick Desaulniers <[email protected]>
chewitt · Apr 8, 2020 · e9e070c · e9e070c
1 parent 5e8ebd8
commit e9e070c
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/arch/x86/Kconfig.assembler b/arch/x86/Kconfig.assembler
@@ -3,15 +3,25 @@
 
 config AS_AVX2
 	def_bool $(as-instr,vpbroadcastb %xmm0$(comma)%ymm1)
+	help
+	  Supported by binutils >= 2.22 and LLVM integrated assembler
 
 config AS_AVX512
 	def_bool $(as-instr,vpmovm2b %k1$(comma)%zmm5)
+	help
+	  Supported by binutils >= 2.25 and LLVM integrated assembler
 
 config AS_SHA1_NI
 	def_bool $(as-instr,sha1msg1 %xmm0$(comma)%xmm1)
+	help
+	  Supported by binutils >= 2.24 and LLVM integrated assembler
 
 config AS_SHA256_NI
 	def_bool $(as-instr,sha256msg1 %xmm0$(comma)%xmm1)
+	help
+	  Supported by binutils >= 2.24 and LLVM integrated assembler
 
 config AS_ADX
 	def_bool $(as-instr,adox %eax$(comma)%eax)
+	help
+	  Supported by binutils >= 2.23 and LLVM integrated assembler