[ARM] Check target feature support for __builtin_arm_crc*

[MaskRay]

Summary

__builtin_arm_crc* requires the target feature crc which is available on armv8
and above. Calling the fuctions for armv7 leads to a SelectionDAG crash.

% clang -c --target=armv7-unknown-linux-gnueabi -c a.c
fatal error: error in backend: Cannot select: intrinsic %llvm.arm.crc32b
PLEASE submit a bug report to ...

Add TARGET_BUILTIN and define required features for these builtins to
report an error in CodeGenFunction::checkTargetFeatures. The problem is quite widespread.
I will add TARGET_BUILTIN for more builtins later.

Fix https://github.com/llvm/llvm-project/issues/57802

[dmgreen]

This looks like a subset of D133359?

[MaskRay]

In D134127#3798442, @dmgreen wrote:

This looks like a subset of D133359?

D133359 looks like it is for AArch64 and may change the diagnostic in a more aggressive way.
This patch seems to be in a suitable granule to fix just this clang crash problem for AArch32...

[dmgreen]

The arm_acle.h header is shared across Arm and AArch64 - they use the same builtin names even if they are replicated to a certain degree across the backends. As this is used in both it would be good to fix them at the same time. It doesn't need to change the guards as D133359 does, the better error message from TARGET_BUILTIN is a good starts (and helps to simplify D133359).

[dmgreen]

Whether you do that here or in another patch, the change LGTM.

[MaskRay]

In D134127#3805748, @dmgreen wrote:

Whether you do that here or in another patch, the change LGTM.

Thanks:) I'll learn more about arm_acle.h

clang/include/clang/Basic/BuiltinsARM.def

 //===----------------------------------------------------------------------===//
 
 // The format of this database matches clang/Basic/Builtins.def.
 
 #if defined(BUILTIN) && !defined(LANGBUILTIN)
 #   define LANGBUILTIN(ID, TYPE, ATTRS, BUILTIN_LANG) BUILTIN(ID, TYPE, ATTRS)
 #endif
 
+#if defined(BUILTIN) && !defined(TARGET_BUILTIN)
+#  define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
 #if defined(BUILTIN) && !defined(TARGET_HEADER_BUILTIN)
 #  define TARGET_HEADER_BUILTIN(ID, TYPE, ATTRS, HEADER, LANG, FEATURE) BUILTIN(ID, TYPE, ATTRS)
 #endif
 
 // In libgcc
 BUILTIN(__clear_cache, "vv*v*", "i")
 
 // 16-bit multiplications

 BUILTIN(__builtin_arm_mrc, "UiUIiUIiUIiUIiUIi", "")
 BUILTIN(__builtin_arm_mrc2, "UiUIiUIiUIiUIiUIi", "")
 BUILTIN(__builtin_arm_mcrr, "vUIiUIiLLUiUIi", "")
 BUILTIN(__builtin_arm_mcrr2, "vUIiUIiLLUiUIi", "")
 BUILTIN(__builtin_arm_mrrc, "LLUiUIiUIiUIi", "")
 BUILTIN(__builtin_arm_mrrc2, "LLUiUIiUIiUIi", "")
 
 // CRC32
-BUILTIN(__builtin_arm_crc32b, "UiUiUc", "nc")
-BUILTIN(__builtin_arm_crc32cb, "UiUiUc", "nc")
-BUILTIN(__builtin_arm_crc32h, "UiUiUs", "nc")
-BUILTIN(__builtin_arm_crc32ch, "UiUiUs", "nc")
-BUILTIN(__builtin_arm_crc32w, "UiUiUi", "nc")
-BUILTIN(__builtin_arm_crc32cw, "UiUiUi", "nc")
-BUILTIN(__builtin_arm_crc32d, "UiUiLLUi", "nc")
-BUILTIN(__builtin_arm_crc32cd, "UiUiLLUi", "nc")
+TARGET_BUILTIN(__builtin_arm_crc32b, "UiUiUc", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32cb, "UiUiUc", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32h, "UiUiUs", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32ch, "UiUiUs", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32w, "UiUiUi", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32cw, "UiUiUi", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32d, "UiUiLLUi", "nc", "crc")
+TARGET_BUILTIN(__builtin_arm_crc32cd, "UiUiLLUi", "nc", "crc")
 
 // ARMv8-M Security Extensions a.k.a CMSE
 BUILTIN(__builtin_arm_cmse_TT, "Uiv*", "n")
 BUILTIN(__builtin_arm_cmse_TTT, "Uiv*", "n")
 BUILTIN(__builtin_arm_cmse_TTA, "Uiv*", "n")
 BUILTIN(__builtin_arm_cmse_TTAT, "Uiv*", "n")
 
 // HINT

clang/lib/Basic/Targets/ARM.cpp

 #include "clang/Basic/BuiltinsNEON.def"
 
 #define BUILTIN(ID, TYPE, ATTRS)                                               \
   {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
 #define LANGBUILTIN(ID, TYPE, ATTRS, LANG)                                     \
   {#ID, TYPE, ATTRS, nullptr, LANG, nullptr},
 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER)                                    \
   {#ID, TYPE, ATTRS, HEADER, ALL_LANGUAGES, nullptr},
+#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
+  {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, FEATURE},
 #define TARGET_HEADER_BUILTIN(ID, TYPE, ATTRS, HEADER, LANGS, FEATURE)         \
   {#ID, TYPE, ATTRS, HEADER, LANGS, FEATURE},
 #include "clang/Basic/BuiltinsARM.def"
 };
 
 ArrayRef<Builtin::Info> ARMTargetInfo::getTargetBuiltins() const {
   return llvm::makeArrayRef(BuiltinInfo, clang::ARM::LastTSBuiltin -
                                              Builtin::FirstTSBuiltin);

clang/test/CodeGen/arm-crc32.c

-// RUN: %clang_cc1 -triple armv8-none-linux-gnueabi \
+// RUN: %clang_cc1 -triple armv8-none-linux-gnueabi -target-feature +crc \
 // RUN:  -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
+// RUN: %clang_cc1 -verify -emit-llvm -triple armv7-none-linux-gnueabi %s
 
 int crc32b(int a, char b)
 {
+// expected-error@+1 {{'__builtin_arm_crc32b' needs target feature crc}}
         return __builtin_arm_crc32b(a,b);
 // CHECK: [[T0:%[0-9]+]] = zext i8 %b to i32
 // CHECK: call i32 @llvm.arm.crc32b(i32 %a, i32 [[T0]])
 }
 
 int crc32cb(int a, char b)
 {
         return __builtin_arm_crc32cb(a,b);