https://github.com/TNorthover created
https://github.com/llvm/llvm-project/pull/85054
It's useful to provide an indicator code with the trap, which the generic
__builtin_trap can't do. asm("brk #N") is an option, but following that with a
__builtin_unreachable() leads to two traps when the compiler doesn't know the
block can't return. So compiler support like this is useful.
>From 73d396865037ebad977d8158f6c66e2c8361dfec Mon Sep 17 00:00:00 2001
From: Tim Northover <tnortho...@apple.com>
Date: Fri, 8 Mar 2024 12:15:53 +0000
Subject: [PATCH] AArch64: add __builtin_arm_trap
It's useful to provide an indicator code with the trap, which the generic
__builtin_trap can't do. asm("brk #N") is an option, but following that with a
__builtin_unreachable() leads to two traps when the compiler doesn't know the
block can't return. So compiler support like this is useful.
---
clang/include/clang/Basic/BuiltinsAArch64.def | 3 +++
clang/lib/CodeGen/CGBuiltin.cpp | 6 ++++++
clang/test/CodeGen/builtins-arm64.c | 6 ++++++
clang/test/Sema/builtins-arm64.c | 9 +++++++++
4 files changed, 24 insertions(+)
diff --git a/clang/include/clang/Basic/BuiltinsAArch64.def
b/clang/include/clang/Basic/BuiltinsAArch64.def
index b5cbe90c8fd6a3..cf8711c6eaee37 100644
--- a/clang/include/clang/Basic/BuiltinsAArch64.def
+++ b/clang/include/clang/Basic/BuiltinsAArch64.def
@@ -50,6 +50,9 @@ BUILTIN(__builtin_arm_wfi, "v", "")
BUILTIN(__builtin_arm_sev, "v", "")
BUILTIN(__builtin_arm_sevl, "v", "")
+// Like __builtin_trap but provide an 16-bit immediate reason code (which goes
into `brk #N`).
+BUILTIN(__builtin_arm_trap, "vUIs", "nr")
+
// CRC32
TARGET_BUILTIN(__builtin_arm_crc32b, "UiUiUc", "nc", "crc")
TARGET_BUILTIN(__builtin_arm_crc32cb, "UiUiUc", "nc", "crc")
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 93ab465079777b..528a13fb275124 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -10686,6 +10686,12 @@ Value
*CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
return Builder.CreateCall(F, llvm::ConstantInt::get(Int32Ty, HintID));
}
+ if (BuiltinID == clang::AArch64::BI__builtin_arm_trap) {
+ Function *F = CGM.getIntrinsic(Intrinsic::aarch64_break);
+ llvm::Value *Arg = EmitScalarExpr(E->getArg(0));
+ return Builder.CreateCall(F, Builder.CreateZExt(Arg, CGM.Int32Ty));
+ }
+
if (BuiltinID == clang::AArch64::BI__builtin_arm_get_sme_state) {
// Create call to __arm_sme_state and store the results to the two
pointers.
CallInst *CI = EmitRuntimeCall(CGM.CreateRuntimeFunction(
diff --git a/clang/test/CodeGen/builtins-arm64.c
b/clang/test/CodeGen/builtins-arm64.c
index 05ea1c719edff3..8bd68d9ceb48ec 100644
--- a/clang/test/CodeGen/builtins-arm64.c
+++ b/clang/test/CodeGen/builtins-arm64.c
@@ -156,4 +156,10 @@ int rndrrs(uint64_t *__addr) {
return __builtin_arm_rndrrs(__addr);
}
+// CHECK-LABEL: @trap(
+// CHECK: call void @llvm.aarch64.break(i32 42)
+void trap() {
+ __builtin_arm_trap(42);
+}
+
// CHECK: ![[M0]] = !{!"1:2:3:4:5"}
diff --git a/clang/test/Sema/builtins-arm64.c b/clang/test/Sema/builtins-arm64.c
index e711121f7260ff..f094162b3aadc9 100644
--- a/clang/test/Sema/builtins-arm64.c
+++ b/clang/test/Sema/builtins-arm64.c
@@ -29,3 +29,12 @@ void test_prefetch(void) {
__builtin_arm_prefetch(0, 0, 0, 2, 0); // expected-error-re {{argument value
{{.*}} is outside the valid range}}
__builtin_arm_prefetch(0, 0, 0, 0, 2); // expected-error-re {{argument value
{{.*}} is outside the valid range}}
}
+
+void test_trap(short s, unsigned short us) {
+ __builtin_arm_trap(42);
+ __builtin_arm_trap(65535);
+ __builtin_arm_trap(-1);
+ __builtin_arm_trap(65536); // expected-warning {{implicit conversion from
'int' to 'unsigned short' changes value from 65536 to 0}}
+ __builtin_arm_trap(s); // expected-error {{argument to '__builtin_arm_trap'
must be a constant integer}}
+ __builtin_arm_trap(us); // expected-error {{argument to '__builtin_arm_trap'
must be a constant integer}}
+}
\ No newline at end of file
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