[PATCH][AArch64][v2] Skip gcc.target/aarch64/assembler_arch_1.c if assembler does not support it

[Kyrill Tkachov]

Hi all,

I've thought about this check a bit more and I think we can compactly 
auto-generate checks
for any aarch64 architecture extension support in the assembler.
This is done in a similar way we autogenerate the arm_arch_*_ok checks for arm.

So in this revision we autogenerate aarch64_asm_<ext>_ok checks for every 
architecture extension
using some of the expect machinery. This should make this approach a bit more 
general to handle
checks for any .arch_extension argument without much extra cost.

This still assumes that the assembler supports the .arch_extension pseudo-op, 
the effective
target check will fail if it doesn't. This is what we want for this testcase.

Is this patch ok instead of 
https://gcc.gnu.org/ml/gcc-patches/2016-02/msg01052.html ?

Thanks,
Kyrill

2016-02-17  Kyrylo Tkachov  <kyrylo.tkac...@arm.com>

    * lib/target-supports.exp: Define aarch64_asm_FUNC_ok checks
    for fp, simd, crypto, crc, lse.
    * doc/sourcebuild.texi (AArch64-specific attributes): Document the
    above.
    * gcc.target/aarch64/assembler_arch_1.c: Add aarch64_asm_lse_ok
    effective target check.

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 6d548aad7aa24c59b40ec13d9c99733d94ec0aa6..19fd938afff9bb480e2262d07ce5c8ff9ca167c7 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -1606,6 +1606,10 @@ ARM target prefers @code{LDRD} and @code{STRD} instructions over
 @subsubsection AArch64-specific attributes
 
 @table @code
+@item aarch64_asm_<ext>_ok
+AArch64 assembler supports the architecture extension @code{ext} via the
+@code{.arch_extension} pseudo-op.  The values of @code{ext} are defined in
+the file config/aarch64/aarch64-option-extensions.def.
 @item aarch64_tiny
 AArch64 target which generates instruction sequences for tiny memory model.
 @item aarch64_small
diff --git a/gcc/testsuite/gcc.target/aarch64/assembler_arch_1.c b/gcc/testsuite/gcc.target/aarch64/assembler_arch_1.c
index 901e50a178d7a4a443a5ad0abe63f624688db268..5deea5cf0ee9306743bc47bace6f762d0e35ce65 100644
--- a/gcc/testsuite/gcc.target/aarch64/assembler_arch_1.c
+++ b/gcc/testsuite/gcc.target/aarch64/assembler_arch_1.c
@@ -1,4 +1,5 @@
 /* { dg-do assemble } */
+/* { dg-require-effective-target aarch64_asm_lse_ok } */
 /* { dg-options "-march=armv8-a" } */
 
 /* Make sure that the function header in assembly doesn't override
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 66fb1eaf7bd4aa58d23cfc9203e9f27573c7a303..f399f185d25aa5a947b7a17fd6020dc311b18f58 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6719,6 +6719,23 @@ proc check_effective_target_aarch64_tiny { } {
     }
 }
 
+# Create functions to check that the AArch64 assembler supports the
+# various architecture extensions via the .arch_extension pseudo-op.
+
+foreach { aarch64_ext } { "fp" "simd" "crypto" "crc" "lse"} {
+    eval [string map [list FUNC $aarch64_ext] {
+	proc check_effective_target_aarch64_asm_FUNC_ok { } {
+	  if { [istarget aarch64*-*-*] } {
+		return [check_no_compiler_messages aarch64_lse_assembler object {
+			__asm__ (".arch_extension FUNC");
+		} "-march=armv8-a+FUNC"]
+	  } else {
+		return 0
+	  }
+	}
+    }]
+}
+
 proc check_effective_target_aarch64_small { } {
     if { [istarget aarch64*-*-*] } {
 	return [check_no_compiler_messages aarch64_small object {