Skip to content

[Clang] Permit implicit conversion from integral to boolean vectors #158369

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Sep 15, 2025
Merged

[Clang] Permit implicit conversion from integral to boolean vectors #158369

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 14 additions & 4 deletions clang/lib/Sema/SemaExpr.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9385,11 +9385,21 @@ AssignConvertType Sema::CheckAssignmentConstraints(QualType LHSType,
return AssignConvertType::Incompatible;
}

// Allow scalar to ExtVector assignments, and assignments of an ExtVector type
// to the same ExtVector type.
if (LHSType->isExtVectorType()) {
if (RHSType->isExtVectorType())
// Allow scalar to ExtVector assignments, assignment to bool, and assignments
// of an ExtVector type to the same ExtVector type.
if (auto *LHSExtType = LHSType->getAs<ExtVectorType>()) {
if (auto *RHSExtType = RHSType->getAs<ExtVectorType>()) {
// Implicit conversions require the same number of elements.
if (LHSExtType->getNumElements() != RHSExtType->getNumElements())
return AssignConvertType::Incompatible;

if (LHSType->isExtVectorBoolType() &&
RHSExtType->getElementType()->isIntegerType()) {
Kind = CK_IntegralToBoolean;
return AssignConvertType::Compatible;
}
return AssignConvertType::Incompatible;
}
if (RHSType->isArithmeticType()) {
// CK_VectorSplat does T -> vector T, so first cast to the element type.
if (ConvertRHS)
Expand Down
15 changes: 12 additions & 3 deletions clang/lib/Sema/SemaOverload.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2162,9 +2162,18 @@ static bool IsVectorConversion(Sema &S, QualType FromType, QualType ToType,

// There are no conversions between extended vector types, only identity.
if (auto *ToExtType = ToType->getAs<ExtVectorType>()) {
if (FromType->getAs<ExtVectorType>()) {
// There are no conversions between extended vector types other than the
// identity conversion.
if (auto *FromExtType = FromType->getAs<ExtVectorType>()) {
// Implicit conversions require the same number of elements.
if (ToExtType->getNumElements() != FromExtType->getNumElements())
return false;

// Permit implicit conversions from integral values to boolean vectors.
if (ToType->isExtVectorBoolType() &&
FromExtType->getElementType()->isIntegerType()) {
ICK = ICK_Boolean_Conversion;
return true;
}
// There are no other conversions between extended vector types.
return false;
}

Expand Down
70 changes: 70 additions & 0 deletions clang/test/CodeGen/vector-convert-boolean.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,70 @@
// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 6
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu %s -emit-llvm -o - | FileCheck %s

using v1i = int [[clang::ext_vector_type(1)]];
using v1b = bool [[clang::ext_vector_type(1)]];
using v8i = int [[clang::ext_vector_type(8)]];
using v8b = bool [[clang::ext_vector_type(8)]];
using v16i = short [[clang::ext_vector_type(16)]];
using v16b = bool [[clang::ext_vector_type(16)]];
using v32i = char [[clang::ext_vector_type(32)]];
using v32b = bool [[clang::ext_vector_type(32)]];

// CHECK-LABEL: define dso_local noundef i8 @_Z3fooDv1_i(
// CHECK-SAME: i32 noundef [[V_COERCE:%.*]]) #[[ATTR0:[0-9]+]] {
// CHECK-NEXT: [[ENTRY:.*:]]
// CHECK-NEXT: [[RETVAL:%.*]] = alloca <1 x i1>, align 1
// CHECK-NEXT: [[V:%.*]] = alloca <1 x i32>, align 4
// CHECK-NEXT: [[V_ADDR:%.*]] = alloca <1 x i32>, align 4
// CHECK-NEXT: store i32 [[V_COERCE]], ptr [[V]], align 4
// CHECK-NEXT: [[V1:%.*]] = load <1 x i32>, ptr [[V]], align 4
// CHECK-NEXT: store <1 x i32> [[V1]], ptr [[V_ADDR]], align 4
// CHECK-NEXT: [[TMP0:%.*]] = load <1 x i32>, ptr [[V_ADDR]], align 4
// CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne <1 x i32> [[TMP0]], zeroinitializer
// CHECK-NEXT: store <1 x i1> [[TOBOOL]], ptr [[RETVAL]], align 1
// CHECK-NEXT: [[TMP1:%.*]] = load i8, ptr [[RETVAL]], align 1
// CHECK-NEXT: ret i8 [[TMP1]]
//
v1b foo(v1i v) { return v; }
// CHECK-LABEL: define dso_local noundef i8 @_Z3fooDv8_i(
// CHECK-SAME: ptr noundef byval(<8 x i32>) align 32 [[TMP0:%.*]]) #[[ATTR0]] {
// CHECK-NEXT: [[ENTRY:.*:]]
// CHECK-NEXT: [[RETVAL:%.*]] = alloca <8 x i1>, align 1
// CHECK-NEXT: [[V_ADDR:%.*]] = alloca <8 x i32>, align 32
// CHECK-NEXT: [[V:%.*]] = load <8 x i32>, ptr [[TMP0]], align 32
// CHECK-NEXT: store <8 x i32> [[V]], ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TMP1:%.*]] = load <8 x i32>, ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne <8 x i32> [[TMP1]], zeroinitializer
// CHECK-NEXT: store <8 x i1> [[TOBOOL]], ptr [[RETVAL]], align 1
// CHECK-NEXT: [[TMP2:%.*]] = load i8, ptr [[RETVAL]], align 1
// CHECK-NEXT: ret i8 [[TMP2]]
//
v8b foo(v8i v) { return v; }
// CHECK-LABEL: define dso_local noundef i16 @_Z3fooDv16_s(
// CHECK-SAME: ptr noundef byval(<16 x i16>) align 32 [[TMP0:%.*]]) #[[ATTR0]] {
// CHECK-NEXT: [[ENTRY:.*:]]
// CHECK-NEXT: [[RETVAL:%.*]] = alloca <16 x i1>, align 2
// CHECK-NEXT: [[V_ADDR:%.*]] = alloca <16 x i16>, align 32
// CHECK-NEXT: [[V:%.*]] = load <16 x i16>, ptr [[TMP0]], align 32
// CHECK-NEXT: store <16 x i16> [[V]], ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TMP1:%.*]] = load <16 x i16>, ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne <16 x i16> [[TMP1]], zeroinitializer
// CHECK-NEXT: store <16 x i1> [[TOBOOL]], ptr [[RETVAL]], align 2
// CHECK-NEXT: [[TMP2:%.*]] = load i16, ptr [[RETVAL]], align 2
// CHECK-NEXT: ret i16 [[TMP2]]
//
v16b foo(v16i v) { return v; }
// CHECK-LABEL: define dso_local noundef i32 @_Z3fooDv32_c(
// CHECK-SAME: ptr noundef byval(<32 x i8>) align 32 [[TMP0:%.*]]) #[[ATTR0]] {
// CHECK-NEXT: [[ENTRY:.*:]]
// CHECK-NEXT: [[RETVAL:%.*]] = alloca <32 x i1>, align 4
// CHECK-NEXT: [[V_ADDR:%.*]] = alloca <32 x i8>, align 32
// CHECK-NEXT: [[V:%.*]] = load <32 x i8>, ptr [[TMP0]], align 32
// CHECK-NEXT: store <32 x i8> [[V]], ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TMP1:%.*]] = load <32 x i8>, ptr [[V_ADDR]], align 32
// CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne <32 x i8> [[TMP1]], zeroinitializer
// CHECK-NEXT: store <32 x i1> [[TOBOOL]], ptr [[RETVAL]], align 4
// CHECK-NEXT: [[TMP2:%.*]] = load i32, ptr [[RETVAL]], align 4
// CHECK-NEXT: ret i32 [[TMP2]]
//
v32b foo(v32i v) { return v; }
29 changes: 29 additions & 0 deletions clang/test/Sema/vector-bool-assign.c
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,29 @@
// RUN: %clang_cc1 -triple x86_64 -fsyntax-only -verify %s

typedef _Bool bool;

typedef __attribute__((ext_vector_type(8))) int v8i;
typedef __attribute__((ext_vector_type(8))) bool v8b;
typedef __attribute__((ext_vector_type(4))) float v4f;
typedef __attribute__((ext_vector_type(4))) bool v4b;

void foo(v8b);

v8b integral(v8i v) {
v8b m1 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) int);
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think it would good to show that these are still narrowing conversions in C++. I did not see any tests that cover this anywhere else.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think I only did assignment, as shown in the changes. I suppose I need to cover the narrowing / initialization case? Unsure where those checks are off the top of my head.

v8b m2 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) unsigned);
v8b m3 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) long);
v8b m4 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) unsigned long);
v8b m5 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) char);
v8b m6 = __builtin_convertvector(v, __attribute__((ext_vector_type(8))) unsigned char);
foo(v);
return v;
}

v4b non_integral(v4f vf) {
return vf; // expected-error{{returning 'v4f' (vector of 4 'float' values) from a function with incompatible result type 'v4b' (vector of 4 'bool' values}}
}

v4b size_mismatch(v8i v) {
return v; // expected-error{{returning 'v8i' (vector of 8 'int' values) from a function with incompatible result type 'v4b' (vector of 4 'bool' values)}}
}
27 changes: 27 additions & 0 deletions clang/test/Sema/vector-bool-assign.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
// RUN: %clang_cc1 -triple x86_64 -fsyntax-only -verify %s

using v8i = int [[clang::ext_vector_type(8)]];
using v8b = bool [[clang::ext_vector_type(8)]];
using v4f = float [[clang::ext_vector_type(4)]];
using v4b = bool [[clang::ext_vector_type(4)]];

void foo(v8b);

v8b integral(v8i v) {
v8b m1 = __builtin_convertvector(v, int [[clang::ext_vector_type(8)]]);
v8b m2 = __builtin_convertvector(v, unsigned [[clang::ext_vector_type(8)]]);
v8b m3 = __builtin_convertvector(v, long [[clang::ext_vector_type(8)]]);
v8b m4 = __builtin_convertvector(v, unsigned long [[clang::ext_vector_type(8)]]);
v8b m5 = __builtin_convertvector(v, char [[clang::ext_vector_type(8)]]);
v8b m6 = __builtin_convertvector(v, unsigned char [[clang::ext_vector_type(8)]]);
foo(v);
return v;
}

v4b non_integral(v4f vf) {
return vf; // expected-error{{cannot initialize return object of type 'v4b' (vector of 4 'bool' values) with an lvalue of type 'v4f' (vector of 4 'float' values)}}
}

v4b size_mismatch(v8i v) {
return v; // expected-error{{cannot initialize return object of type 'v4b' (vector of 4 'bool' values) with an lvalue of type 'v8i' (vector of 8 'int' values)}}
}
Loading