[clang] [AArch64] Warn when calling a NEON builtin in a streaming function (PR #73672)
Sam Tebbs via cfe-commits
cfe-commits at lists.llvm.org
Tue Nov 28 09:21:42 PST 2023
https://github.com/SamTebbs33 created https://github.com/llvm/llvm-project/pull/73672
This patch introduces a warning that is emitted when a Neon builtin is called from a streaming function, as that situation is not supported.
Uses work by Kerry McLaughlin.
>From 96464a9c37a532216e4df6c003aa1a8fcb448637 Mon Sep 17 00:00:00 2001
From: Samuel Tebbs <samuel.tebbs at arm.com>
Date: Tue, 28 Nov 2023 16:22:32 +0000
Subject: [PATCH] [AArch64] Warn when calling a NEON builtin in a streaming
function
This patch introduces a warning that is emitted when a Neon builtin is called from a streaming function, as that situation is not supported.
---
.../clang/Basic/DiagnosticSemaKinds.td | 3 +
clang/lib/Sema/SemaChecking.cpp | 81 +++++++++++++++++++
.../Sema/aarch64-incompat-sm-builtin-calls.c | 24 ++++++
3 files changed, 108 insertions(+)
create mode 100644 clang/test/Sema/aarch64-incompat-sm-builtin-calls.c
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 9a7dafa4a298273..e2b7a695322c14b 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3148,6 +3148,9 @@ def err_attribute_bad_sve_vector_size : Error<
def err_attribute_arm_feature_sve_bits_unsupported : Error<
"%0 is only supported when '-msve-vector-bits=<bits>' is specified with a "
"value of 128, 256, 512, 1024 or 2048.">;
+def warn_attribute_arm_sm_incompat_builtin : Warning<
+ "builtin call has undefined behaviour when called from a %0 function">,
+ InGroup<DiagGroup<"undefined-arm-streaming">>;
def err_sve_vector_in_non_sve_target : Error<
"SVE vector type %0 cannot be used in a target without sve">;
def err_attribute_riscv_rvv_bits_unsupported : Error<
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index ae588db02bbe722..07937047a2843b0 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -2993,6 +2993,62 @@ static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context,
llvm_unreachable("Invalid NeonTypeFlag!");
}
+enum ArmStreamingType {
+ ArmNonStreaming,
+ ArmStreaming,
+ ArmStreamingCompatible,
+ ArmLocallyStreaming,
+ ArmStreamingOrSVE2p1
+};
+
+static ArmStreamingType getArmStreamingFnType(const FunctionDecl *FD) {
+ if (FD->hasAttr<ArmLocallyStreamingAttr>())
+ return ArmLocallyStreaming;
+ if (const auto *T = FD->getType()->getAs<FunctionProtoType>()) {
+ if (T->getAArch64SMEAttributes() & FunctionType::SME_PStateSMEnabledMask)
+ return ArmStreaming;
+ if (T->getAArch64SMEAttributes() & FunctionType::SME_PStateSMCompatibleMask)
+ return ArmStreamingCompatible;
+ }
+ return ArmNonStreaming;
+}
+
+static void checkArmStreamingBuiltin(Sema &S, CallExpr *TheCall,
+ const FunctionDecl *FD,
+ ArmStreamingType BuiltinType) {
+ assert(BuiltinType != ArmLocallyStreaming &&
+ "Unexpected locally_streaming attribute for builtin!");
+
+ ArmStreamingType FnType = getArmStreamingFnType(FD);
+ if (BuiltinType == ArmStreamingOrSVE2p1) {
+ // Check intrinsics that are available in [sve2p1 or sme/sme2].
+ llvm::StringMap<bool> CallerFeatureMap;
+ S.Context.getFunctionFeatureMap(CallerFeatureMap, FD);
+ if (Builtin::evaluateRequiredTargetFeatures("sve2p1", CallerFeatureMap))
+ BuiltinType = ArmStreamingCompatible;
+ else
+ BuiltinType = ArmStreaming;
+ }
+
+ if ((FnType == ArmStreaming || FnType == ArmLocallyStreaming) &&
+ BuiltinType == ArmNonStreaming) {
+ S.Diag(TheCall->getBeginLoc(), diag::warn_attribute_arm_sm_incompat_builtin)
+ << TheCall->getSourceRange() << "streaming or locally streaming";
+ }
+
+ if ((FnType == ArmStreamingCompatible) &&
+ BuiltinType != ArmStreamingCompatible) {
+ S.Diag(TheCall->getBeginLoc(), diag::warn_attribute_arm_sm_incompat_builtin)
+ << TheCall->getSourceRange() << "streaming compatible";
+ return;
+ }
+
+ if (FnType == ArmNonStreaming && BuiltinType == ArmStreaming) {
+ S.Diag(TheCall->getBeginLoc(), diag::warn_attribute_arm_sm_incompat_builtin)
+ << TheCall->getSourceRange() << "non-streaming";
+ }
+}
+
bool Sema::CheckSVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
// Range check SVE intrinsics that take immediate values.
SmallVector<std::tuple<int,int,int>, 3> ImmChecks;
@@ -3136,6 +3192,31 @@ bool Sema::CheckSVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
bool Sema::CheckNeonBuiltinFunctionCall(const TargetInfo &TI,
unsigned BuiltinID, CallExpr *TheCall) {
+ if (const FunctionDecl *FD = getCurFunctionDecl()) {
+ std::optional<ArmStreamingType> BuiltinType;
+
+ bool IsNeon = false;
+ switch (BuiltinID) {
+ default:
+ break;
+#define GET_NEON_BUILTINS
+#define TARGET_BUILTIN(id, x, y, z) \
+ case NEON::BI##id: \
+ IsNeon = true; \
+ break;
+#define BUILTIN(id, x, y) TARGET_BUILTIN(id, x, y, "");
+#include "clang/Basic/arm_neon.inc"
+#undef TARGET_BUILTIN
+#undef BUILTIN
+#undef GET_NEON_BUILTINS
+ }
+
+ if (IsNeon) {
+ checkArmStreamingBuiltin(*this, TheCall, FD, ArmNonStreaming);
+ return true;
+ }
+ }
+
llvm::APSInt Result;
uint64_t mask = 0;
unsigned TV = 0;
diff --git a/clang/test/Sema/aarch64-incompat-sm-builtin-calls.c b/clang/test/Sema/aarch64-incompat-sm-builtin-calls.c
new file mode 100644
index 000000000000000..08ed22917da67ca
--- /dev/null
+++ b/clang/test/Sema/aarch64-incompat-sm-builtin-calls.c
@@ -0,0 +1,24 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve \
+// RUN: -target-feature +sme -target-feature +sve2 -target-feature +neon -fsyntax-only -verify %s
+
+// REQUIRES: aarch64-registered-target
+
+#include "arm_neon.h"
+#include "arm_sme_draft_spec_subject_to_change.h"
+#include "arm_sve.h"
+
+int16x8_t incompat_neon_sm(int16x8_t splat) __arm_streaming {
+ // expected-warning at +1 {{builtin call has undefined behaviour when called from a streaming or locally streaming function}}
+ return (int16x8_t)__builtin_neon_vqaddq_v((int8x16_t)splat, (int8x16_t)splat, 33);
+}
+
+__arm_locally_streaming int16x8_t incompat_neon_ls(int16x8_t splat) {
+ // expected-warning at +1 {{builtin call has undefined behaviour when called from a streaming or locally streaming function}}
+ return (int16x8_t)__builtin_neon_vqaddq_v((int8x16_t)splat, (int8x16_t)splat, 33);
+}
+
+int16x8_t incompat_neon_smc(int16x8_t splat) __arm_streaming_compatible {
+ // expected-warning at +1 {{builtin call has undefined behaviour when called from a streaming compatible function}}
+ return (int16x8_t)__builtin_neon_vqaddq_v((int8x16_t)splat, (int8x16_t)splat, 33);
+}
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