Reland r374450 with Richard Smith's comments and test fixed.
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment. Instead, we're just
assuming the maximum possible alignment.
Differential Revision: https://reviews.llvm.org/D68824
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374562 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index bcd059b..47a1dee 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2853,6 +2853,10 @@
def err_attribute_aligned_too_great : Error<
"requested alignment must be %0 bytes or smaller">;
+def warn_assume_aligned_too_great
+ : Warning<"requested alignment must be %0 bytes or smaller; maximum "
+ "alignment assumed">,
+ InGroup<DiagGroup<"builtin-assume-aligned-alignment">>;
def warn_redeclaration_without_attribute_prev_attribute_ignored : Warning<
"%q0 redeclared without %1 attribute: previous %1 ignored">,
InGroup<MicrosoftInconsistentDllImport>;
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 0562a62..ddff595 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -2048,11 +2048,13 @@
Value *AlignmentValue = EmitScalarExpr(E->getArg(1));
ConstantInt *AlignmentCI = cast<ConstantInt>(AlignmentValue);
- unsigned Alignment = (unsigned)AlignmentCI->getZExtValue();
+ if (AlignmentCI->getValue().ugt(llvm::Value::MaximumAlignment))
+ AlignmentCI = ConstantInt::get(AlignmentCI->getType(),
+ llvm::Value::MaximumAlignment);
EmitAlignmentAssumption(PtrValue, Ptr,
/*The expr loc is sufficient.*/ SourceLocation(),
- Alignment, OffsetValue);
+ AlignmentCI, OffsetValue);
return RValue::get(PtrValue);
}
case Builtin::BI__assume:
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 682a7cc..2ec9e91 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -4569,7 +4569,7 @@
llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment);
EmitAlignmentAssumption(Ret.getScalarVal(), RetTy, Loc, AA->getLocation(),
- AlignmentCI->getZExtValue(), OffsetValue);
+ AlignmentCI, OffsetValue);
} else if (const auto *AA = TargetDecl->getAttr<AllocAlignAttr>()) {
llvm::Value *AlignmentVal = CallArgs[AA->getParamIndex().getLLVMIndex()]
.getRValue(*this)
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 0b9271b..c7f279d 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -294,8 +294,7 @@
Value *AlignmentValue = CGF.EmitScalarExpr(AVAttr->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(AlignmentValue);
- CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(),
- AlignmentCI->getZExtValue());
+ CGF.EmitAlignmentAssumption(V, E, AVAttr->getLocation(), AlignmentCI);
}
/// EmitLoadOfLValue - Given an expression with complex type that represents a
diff --git a/lib/CodeGen/CGStmtOpenMP.cpp b/lib/CodeGen/CGStmtOpenMP.cpp
index e50cdb1..2a4e89b 100644
--- a/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/lib/CodeGen/CGStmtOpenMP.cpp
@@ -1519,14 +1519,14 @@
if (!CGF.HaveInsertPoint())
return;
for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
- unsigned ClauseAlignment = 0;
+ llvm::APInt ClauseAlignment(64, 0);
if (const Expr *AlignmentExpr = Clause->getAlignment()) {
auto *AlignmentCI =
cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
- ClauseAlignment = static_cast<unsigned>(AlignmentCI->getZExtValue());
+ ClauseAlignment = AlignmentCI->getValue();
}
for (const Expr *E : Clause->varlists()) {
- unsigned Alignment = ClauseAlignment;
+ llvm::APInt Alignment(ClauseAlignment);
if (Alignment == 0) {
// OpenMP [2.8.1, Description]
// If no optional parameter is specified, implementation-defined default
@@ -1537,12 +1537,13 @@
E->getType()->getPointeeType()))
.getQuantity();
}
- assert((Alignment == 0 || llvm::isPowerOf2_32(Alignment)) &&
+ assert((Alignment == 0 || Alignment.isPowerOf2()) &&
"alignment is not power of 2");
if (Alignment != 0) {
llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
CGF.EmitAlignmentAssumption(
- PtrValue, E, /*No second loc needed*/ SourceLocation(), Alignment);
+ PtrValue, E, /*No second loc needed*/ SourceLocation(),
+ llvm::ConstantInt::get(CGF.getLLVMContext(), Alignment));
}
}
}
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 41b7f2f..3f9a52a 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -2057,24 +2057,9 @@
}
void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
- QualType Ty, SourceLocation Loc,
- SourceLocation AssumptionLoc,
- unsigned Alignment,
- llvm::Value *OffsetValue) {
- llvm::Value *TheCheck;
- llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
- CGM.getDataLayout(), PtrValue, Alignment, OffsetValue, &TheCheck);
- if (SanOpts.has(SanitizerKind::Alignment)) {
- llvm::Value *AlignmentVal = llvm::ConstantInt::get(IntPtrTy, Alignment);
- EmitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, AlignmentVal,
- OffsetValue, TheCheck, Assumption);
- }
-}
-
-void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
const Expr *E,
SourceLocation AssumptionLoc,
- unsigned Alignment,
+ llvm::Value *Alignment,
llvm::Value *OffsetValue) {
if (auto *CE = dyn_cast<CastExpr>(E))
E = CE->getSubExprAsWritten();
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index ea78309..bb4fed8 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -2829,13 +2829,8 @@
llvm::Value *Alignment,
llvm::Value *OffsetValue = nullptr);
- void EmitAlignmentAssumption(llvm::Value *PtrValue, QualType Ty,
- SourceLocation Loc, SourceLocation AssumptionLoc,
- unsigned Alignment,
- llvm::Value *OffsetValue = nullptr);
-
void EmitAlignmentAssumption(llvm::Value *PtrValue, const Expr *E,
- SourceLocation AssumptionLoc, unsigned Alignment,
+ SourceLocation AssumptionLoc, llvm::Value *Alignment,
llvm::Value *OffsetValue = nullptr);
//===--------------------------------------------------------------------===//
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 07d3648..dca81d1 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -6063,6 +6063,12 @@
if (!Result.isPowerOf2())
return Diag(TheCall->getBeginLoc(), diag::err_alignment_not_power_of_two)
<< Arg->getSourceRange();
+
+ // Alignment calculations can wrap around if it's greater than 2**29.
+ unsigned MaximumAlignment = 536870912;
+ if (Result > MaximumAlignment)
+ Diag(TheCall->getBeginLoc(), diag::warn_assume_aligned_too_great)
+ << Arg->getSourceRange() << MaximumAlignment;
}
if (NumArgs > 2) {
diff --git a/test/CodeGen/builtin-assume-aligned.c b/test/CodeGen/builtin-assume-aligned.c
index 1d807a4..f6a89a2 100644
--- a/test/CodeGen/builtin-assume-aligned.c
+++ b/test/CodeGen/builtin-assume-aligned.c
@@ -65,3 +65,12 @@
// CHECK: call void @llvm.assume(i1 [[MASKCOND6]])
}
+// CHECK-LABEL: @pr43638
+int pr43638(int *a) {
+ a = __builtin_assume_aligned(a, 4294967296);
+return a[0];
+// CHECK: [[PTRINT7:%.+]] = ptrtoint
+// CHECK: [[MASKEDPTR7:%.+]] = and i64 [[PTRINT7]], 536870911
+// CHECK: [[MASKCOND7:%.+]] = icmp eq i64 [[MASKEDPTR7]], 0
+// CHECK: call void @llvm.assume(i1 [[MASKCOND7]])
+}
diff --git a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params-variable.cpp b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params-variable.cpp
index 4384b9c..4306e32 100644
--- a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params-variable.cpp
+++ b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params-variable.cpp
@@ -18,13 +18,13 @@
// CHECK-NEXT: %[[OFFSET_RELOADED:.*]] = load i64, i64* %[[OFFSET_ADDR]], align 8
// CHECK-NEXT: %[[PTRINT:.*]] = ptrtoint i8* %[[BITCAST]] to i64
// CHECK-NEXT: %[[OFFSETPTR:.*]] = sub i64 %[[PTRINT]], %[[OFFSET_RELOADED]]
- // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[OFFSETPTR]], 2147483647
+ // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[OFFSETPTR]], 536870911
// CHECK-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0
// CHECK-SANITIZE-NEXT: %[[PTRINT_DUP:.*]] = ptrtoint i8* %[[BITCAST]] to i64, !nosanitize
// CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT:.*]], label %[[HANDLER_ALIGNMENT_ASSUMPTION:[^,]+]],{{.*}} !nosanitize
// CHECK-SANITIZE: [[HANDLER_ALIGNMENT_ASSUMPTION]]:
- // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 %[[OFFSET_RELOADED]]){{.*}}, !nosanitize
- // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 %[[OFFSET_RELOADED]]){{.*}}, !nosanitize
+ // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 %[[OFFSET_RELOADED]]){{.*}}, !nosanitize
+ // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 %[[OFFSET_RELOADED]]){{.*}}, !nosanitize
// CHECK-SANITIZE-TRAP-NEXT: call void @llvm.trap(){{.*}}, !nosanitize
// CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
// CHECK-SANITIZE: [[CONT]]:
diff --git a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params.cpp b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params.cpp
index 18a5734..27f53e9 100644
--- a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params.cpp
+++ b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-three-params.cpp
@@ -15,13 +15,13 @@
// CHECK-NEXT: %[[BITCAST:.*]] = bitcast i8** %[[X_RELOADED]] to i8*
// CHECK-NEXT: %[[PTRINT:.*]] = ptrtoint i8* %[[BITCAST]] to i64
// CHECK-NEXT: %[[OFFSETPTR:.*]] = sub i64 %[[PTRINT]], 42
- // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[OFFSETPTR]], 2147483647
+ // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[OFFSETPTR]], 536870911
// CHECK-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0
// CHECK-SANITIZE-NEXT: %[[PTRINT_DUP:.*]] = ptrtoint i8* %[[BITCAST]] to i64, !nosanitize
// CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT:.*]], label %[[HANDLER_ALIGNMENT_ASSUMPTION:[^,]+]],{{.*}} !nosanitize
// CHECK-SANITIZE: [[HANDLER_ALIGNMENT_ASSUMPTION]]:
- // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 42){{.*}}, !nosanitize
- // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 42){{.*}}, !nosanitize
+ // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 42){{.*}}, !nosanitize
+ // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 42){{.*}}, !nosanitize
// CHECK-SANITIZE-TRAP-NEXT: call void @llvm.trap(){{.*}}, !nosanitize
// CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
// CHECK-SANITIZE: [[CONT]]:
diff --git a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-two-params.cpp b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-two-params.cpp
index fe43847..5412270 100644
--- a/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-two-params.cpp
+++ b/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-two-params.cpp
@@ -14,13 +14,13 @@
// CHECK-NEXT: %[[X_RELOADED:.*]] = load i8**, i8*** %[[X_ADDR]], align 8
// CHECK-NEXT: %[[BITCAST:.*]] = bitcast i8** %[[X_RELOADED]] to i8*
// CHECK-NEXT: %[[PTRINT:.*]] = ptrtoint i8* %[[BITCAST]] to i64
- // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[PTRINT]], 2147483647
+ // CHECK-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[PTRINT]], 536870911
// CHECK-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0
// CHECK-SANITIZE-NEXT: %[[PTRINT_DUP:.*]] = ptrtoint i8* %[[BITCAST]] to i64, !nosanitize
// CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT:.*]], label %[[HANDLER_ALIGNMENT_ASSUMPTION:[^,]+]],{{.*}} !nosanitize
// CHECK-SANITIZE: [[HANDLER_ALIGNMENT_ASSUMPTION]]:
- // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 0){{.*}}, !nosanitize
- // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 2147483648, i64 0){{.*}}, !nosanitize
+ // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 0){{.*}}, !nosanitize
+ // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 536870912, i64 0){{.*}}, !nosanitize
// CHECK-SANITIZE-TRAP-NEXT: call void @llvm.trap(){{.*}}, !nosanitize
// CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
// CHECK-SANITIZE: [[CONT]]:
diff --git a/test/Sema/builtin-assume-aligned.c b/test/Sema/builtin-assume-aligned.c
index 057a500..9411cb4 100644
--- a/test/Sema/builtin-assume-aligned.c
+++ b/test/Sema/builtin-assume-aligned.c
@@ -58,3 +58,7 @@
void *test_no_fn_proto() __attribute__((assume_aligned())); // expected-error {{'assume_aligned' attribute takes at least 1 argument}}
void *test_no_fn_proto() __attribute__((assume_aligned(32, 45, 37))); // expected-error {{'assume_aligned' attribute takes no more than 2 arguments}}
+int pr43638(int *a) {
+ a = __builtin_assume_aligned(a, 4294967296); // expected-warning {{requested alignment must be 536870912 bytes or smaller; maximum alignment assumed}}
+return a[0];
+}
