From: Andrew Carlotti <andrew.carlotti@arm.com>
Date: Fri, 24 Nov 2023 17:06:07 +0000 (+0000)
Subject: aarch64: Fix +nocrypto handling
X-Git-Tag: basepoints/gcc-15~3527
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8d30107455f2309854ced3d65fb07dc1f2c357c0;p=thirdparty%2Fgcc.git

aarch64: Fix +nocrypto handling

Additionally, replace all checks for the AARCH64_FL_CRYPTO bit with
checks for (AARCH64_FL_AES | AARCH64_FL_SHA2) instead.  The value of the
AARCH64_FL_CRYPTO bit within isa_flags is now ignored, but it is
retained because removing it would make processing the data in
option-extensions.def significantly more complex.

This bug should have been picked up by an existing test, but a missing
newline meant that the pattern incorrectly allowed "+crypto+nocrypto".

gcc/ChangeLog:

	* common/config/aarch64/aarch64-common.cc
	(aarch64_get_extension_string_for_isa_flags): Fix generation of
	the "+nocrypto" extension.
	* config/aarch64/aarch64.h (AARCH64_ISA_CRYPTO): Remove.
	(TARGET_CRYPTO): Remove.
	* config/aarch64/aarch64-c.cc (aarch64_update_cpp_builtins):
	Don't use TARGET_CRYPTO.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/options_set_4.c: Add terminating newline.
	* gcc.target/aarch64/options_set_27.c: New test.
---

diff --git a/gcc/common/config/aarch64/aarch64-common.cc b/gcc/common/config/aarch64/aarch64-common.cc
index 8fb901029ec2..c2a6d357c0bc 100644
--- a/gcc/common/config/aarch64/aarch64-common.cc
+++ b/gcc/common/config/aarch64/aarch64-common.cc
@@ -311,6 +311,7 @@ aarch64_get_extension_string_for_isa_flags
      But in order to make the output more readable, it seems better
      to add the strings in definition order.  */
   aarch64_feature_flags added = 0;
+  auto flags_crypto = AARCH64_FL_AES | AARCH64_FL_SHA2;
   for (unsigned int i = ARRAY_SIZE (all_extensions); i-- > 0; )
     {
       auto &opt = all_extensions[i];
@@ -320,7 +321,7 @@ aarch64_get_extension_string_for_isa_flags
 	 per-feature crypto flags.  */
       auto flags = opt.flag_canonical;
       if (flags == AARCH64_FL_CRYPTO)
-	flags = AARCH64_FL_AES | AARCH64_FL_SHA2;
+	flags = flags_crypto;
 
       if ((flags & isa_flags & (explicit_flags | ~current_flags)) == flags)
 	{
@@ -339,14 +340,32 @@ aarch64_get_extension_string_for_isa_flags
      not have an HWCAPs then it shouldn't be taken into account for feature
      detection because one way or another we can't tell if it's available
      or not.  */
+
   for (auto &opt : all_extensions)
-    if (opt.native_detect_p
-	&& (opt.flag_canonical & current_flags & ~isa_flags))
-      {
-	current_flags &= ~opt.flags_off;
-	outstr += "+no";
-	outstr += opt.name;
-      }
+    {
+      auto flags = opt.flag_canonical;
+      /* As a special case, don't emit "+noaes" or "+nosha2" when we could emit
+	 "+nocrypto" instead, in order to support assemblers that predate the
+	 separate per-feature crypto flags.  Only allow "+nocrypto" when "sm4"
+	 is not already enabled (to avoid dependending on whether "+nocrypto"
+	 also disables "sm4").  */
+      if (flags & flags_crypto
+	  && (flags_crypto & current_flags & ~isa_flags) == flags_crypto
+	  && !(current_flags & AARCH64_FL_SM4))
+	  continue;
+
+      if (flags == AARCH64_FL_CRYPTO)
+	/* If either crypto flag needs removing here, then both do.  */
+	flags = flags_crypto;
+
+      if (opt.native_detect_p
+	  && (flags & current_flags & ~isa_flags))
+	{
+	  current_flags &= ~opt.flags_off;
+	  outstr += "+no";
+	  outstr += opt.name;
+	}
+    }
 
   return outstr;
 }
diff --git a/gcc/config/aarch64/aarch64-c.cc b/gcc/config/aarch64/aarch64-c.cc
index 05ad763b871b..d4ed1bfcb3a6 100644
--- a/gcc/config/aarch64/aarch64-c.cc
+++ b/gcc/config/aarch64/aarch64-c.cc
@@ -188,7 +188,7 @@ aarch64_update_cpp_builtins (cpp_reader *pfile)
   aarch64_def_or_undef (TARGET_ILP32, "_ILP32", pfile);
   aarch64_def_or_undef (TARGET_ILP32, "__ILP32__", pfile);
 
-  aarch64_def_or_undef (TARGET_CRYPTO, "__ARM_FEATURE_CRYPTO", pfile);
+  aarch64_def_or_undef (TARGET_AES && TARGET_SHA2, "__ARM_FEATURE_CRYPTO", pfile);
   aarch64_def_or_undef (TARGET_SIMD_RDMA, "__ARM_FEATURE_QRDMX", pfile);
   aarch64_def_or_undef (TARGET_SVE, "__ARM_FEATURE_SVE", pfile);
   cpp_undef (pfile, "__ARM_FEATURE_SVE_BITS");
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 2cd0bc552eba..501bb7478a07 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -204,7 +204,11 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = AARCH64_FL_SM_OFF;
 
 #endif
 
-/* Macros to test ISA flags.  */
+/* Macros to test ISA flags.
+
+   There is intentionally no macro for AARCH64_FL_CRYPTO, since this flag bit
+   is not always set when its constituent features are present.
+   Check (TARGET_AES && TARGET_SHA2) instead.  */
 
 #define AARCH64_ISA_SM_OFF         (aarch64_isa_flags & AARCH64_FL_SM_OFF)
 #define AARCH64_ISA_SM_ON          (aarch64_isa_flags & AARCH64_FL_SM_ON)
@@ -213,7 +217,6 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = AARCH64_FL_SM_OFF;
 #define AARCH64_ISA_V8A		   (aarch64_isa_flags & AARCH64_FL_V8A)
 #define AARCH64_ISA_V8_1A	   (aarch64_isa_flags & AARCH64_FL_V8_1A)
 #define AARCH64_ISA_CRC            (aarch64_isa_flags & AARCH64_FL_CRC)
-#define AARCH64_ISA_CRYPTO         (aarch64_isa_flags & AARCH64_FL_CRYPTO)
 #define AARCH64_ISA_FP             (aarch64_isa_flags & AARCH64_FL_FP)
 #define AARCH64_ISA_SIMD           (aarch64_isa_flags & AARCH64_FL_SIMD)
 #define AARCH64_ISA_LSE		   (aarch64_isa_flags & AARCH64_FL_LSE)
@@ -294,9 +297,6 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = AARCH64_FL_SM_OFF;
 #define AARCH64_FL_SCXTNUM	   AARCH64_FL_V8_5A
 #define AARCH64_FL_ID_PFR2	   AARCH64_FL_V8_5A
 
-/* Crypto is an optional extension to AdvSIMD.  */
-#define TARGET_CRYPTO (AARCH64_ISA_CRYPTO)
-
 /* SHA2 is an optional extension to AdvSIMD.  */
 #define TARGET_SHA2 (AARCH64_ISA_SHA2)
 
diff --git a/gcc/testsuite/gcc.target/aarch64/options_set_27.c b/gcc/testsuite/gcc.target/aarch64/options_set_27.c
new file mode 100644
index 000000000000..e35744640130
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/options_set_27.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=armv8.2-a+aes+sha3" } */
+
+int main ()
+{
+  return 0;
+}
+
+/* { dg-final { scan-assembler-times {\.arch armv8\.2\-a\+crc\+aes\+sha3\n} 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/options_set_4.c b/gcc/testsuite/gcc.target/aarch64/options_set_4.c
index 5370e02e1531..7b00d09a47f0 100644
--- a/gcc/testsuite/gcc.target/aarch64/options_set_4.c
+++ b/gcc/testsuite/gcc.target/aarch64/options_set_4.c
@@ -6,7 +6,7 @@ int main ()
   return 0;
 }
 
-/* { dg-final { scan-assembler-times {\.arch armv8\.2\-a\+crc\+crypto} 1 } } */
+/* { dg-final { scan-assembler-times {\.arch armv8\.2\-a\+crc\+crypto\n} 1 } } */
 
 /* Check if individual bits that make up a grouping is specified that only the
    grouping is kept. */