[clang] bc53832 - [clang][RISCV] Fix incorrect ABI lowering for inherited structs under hard-float ABIs
Alex Bradbury via cfe-commits
cfe-commits at lists.llvm.org
Fri Aug 19 12:32:24 PDT 2022
Author: Alex Bradbury
Date: 2022-08-19T20:31:06+01:00
New Revision: bc538320809fb52af12ec0366118c82201af4f40
URL: https://github.com/llvm/llvm-project/commit/bc538320809fb52af12ec0366118c82201af4f40
DIFF: https://github.com/llvm/llvm-project/commit/bc538320809fb52af12ec0366118c82201af4f40.diff
LOG: [clang][RISCV] Fix incorrect ABI lowering for inherited structs under hard-float ABIs
The hard float ABIs have a rule that if a flattened struct contains
either a single fp value, or an int+fp, or fp+fp then it may be passed
in a pair of registers (if sufficient GPRs+FPRs are available).
detectFPCCEligibleStruct and the helper it calls,
detectFPCCEligibleStructHelper examine the type of the argument/return
value to determine if it complies with the requirements for this ABI
rule.
As reported in bug #57084, this logic produces incorrect results for C++
structs that inherit from other structs. This is because only the fields
of the struct were examined, but enumerating RD->fields misses any
fields in inherited C++ structs. This patch corrects that issue by
adding appropriate logic to enumerate any included base structs.
Differential Revision: https://reviews.llvm.org/D131677
Added:
Modified:
clang/lib/CodeGen/TargetInfo.cpp
clang/test/CodeGen/RISCV/riscv-abi.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 39871b0907ede..1f9c903effca8 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -10979,9 +10979,22 @@ bool RISCVABIInfo::detectFPCCEligibleStructHelper(QualType Ty, CharUnits CurOff,
// Unions aren't eligible unless they're empty (which is caught above).
if (RD->isUnion())
return false;
+ const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
+ // If this is a C++ record, check the bases first.
+ if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
+ for (const CXXBaseSpecifier &B : CXXRD->bases()) {
+ const auto *BDecl =
+ cast<CXXRecordDecl>(B.getType()->castAs<RecordType>()->getDecl());
+ CharUnits BaseOff = Layout.getBaseClassOffset(BDecl);
+ bool Ret = detectFPCCEligibleStructHelper(B.getType(), CurOff + BaseOff,
+ Field1Ty, Field1Off, Field2Ty,
+ Field2Off);
+ if (!Ret)
+ return false;
+ }
+ }
int ZeroWidthBitFieldCount = 0;
for (const FieldDecl *FD : RD->fields()) {
- const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
uint64_t FieldOffInBits = Layout.getFieldOffset(FD->getFieldIndex());
QualType QTy = FD->getType();
if (FD->isBitField()) {
diff --git a/clang/test/CodeGen/RISCV/riscv-abi.cpp b/clang/test/CodeGen/RISCV/riscv-abi.cpp
index ba9e61bbbe7db..7e34ffef14d30 100644
--- a/clang/test/CodeGen/RISCV/riscv-abi.cpp
+++ b/clang/test/CodeGen/RISCV/riscv-abi.cpp
@@ -1,15 +1,15 @@
-// RUN: %clang_cc1 -triple riscv32 -emit-llvm -x c++ %s -o - \
+// RUN: %clang_cc1 -triple riscv32 -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=ILP32,ILP32-ILP32F,ILP32-ILP32F-ILP32D %s
-// RUN: %clang_cc1 -triple riscv32 -target-feature +f -target-abi ilp32f -emit-llvm -x c++ %s -o - \
+// RUN: %clang_cc1 -triple riscv32 -target-feature +f -target-abi ilp32f -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=ILP32F,ILP32-ILP32F,ILP32F-ILP32D,ILP32-ILP32F-ILP32D %s
-// RUN: %clang_cc1 -triple riscv32 -target-feature +f -target-feature +d -target-abi ilp32d -emit-llvm %s -x c++ -o - \
+// RUN: %clang_cc1 -triple riscv32 -target-feature +f -target-feature +d -target-abi ilp32d -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=ILP32D,ILP32F-ILP32D,ILP32-ILP32F-ILP32D %s
-// RUN: %clang_cc1 -triple riscv64 -emit-llvm -x c++ %s -o - \
+// RUN: %clang_cc1 -triple riscv64 -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=LP64,LP64-LP64F,LP64-LP64F-LP64D %s
-// RUN: %clang_cc1 -triple riscv64 -target-feature +f -target-abi lp64f -emit-llvm -x c++ %s -o - \
+// RUN: %clang_cc1 -triple riscv64 -target-feature +f -target-abi lp64f -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=LP64F,LP64-LP64F,LP64F-LP64D,LP64-LP64F-LP64D %s
-// RUN: %clang_cc1 -triple riscv64 -target-feature +f -target-feature +d -target-abi lp64d -emit-llvm %s -x c++ -o - \
+// RUN: %clang_cc1 -triple riscv64 -target-feature +f -target-feature +d -target-abi lp64d -emit-llvm %s -o - \
// RUN: | FileCheck -check-prefixes=LP64D,LP64F-LP64D,LP64-LP64F-LP64D %s
#include <stdint.h>
@@ -39,12 +39,10 @@ struct child2_float_s : parent2_int32_s {
float f1;
};
-// TODO: Fix incorrect lowering for hard-float ABIs.
-
// ILP32: define{{.*}} [2 x i32] @_Z30int32_float_struct_inheritance14child2_float_s([2 x i32] %a.coerce)
-// ILP32F-ILP32D: define{{.*}} float @_Z30int32_float_struct_inheritance14child2_float_s(float %0)
+// ILP32F-ILP32D: define{{.*}} { i32, float } @_Z30int32_float_struct_inheritance14child2_float_s(i32 %0, float %1)
// LP64: define{{.*}} i64 @_Z30int32_float_struct_inheritance14child2_float_s(i64 %a.coerce)
-// LP64F-LP64D: define{{.*}} float @_Z30int32_float_struct_inheritance14child2_float_s(float %0)
+// LP64F-LP64D: define{{.*}} { i32, float } @_Z30int32_float_struct_inheritance14child2_float_s(i32 %0, float %1)
struct child2_float_s int32_float_struct_inheritance(struct child2_float_s a) {
return a;
}
@@ -57,10 +55,9 @@ struct child3_int64_s : parent3_float_s {
int64_t i1;
};
-// TODO: Fix incorrect lowering for lp64f/lp64d ABIs.
-
// ILP32-ILP32F-ILP32D-LABEL: define{{.*}} void @_Z30float_int64_struct_inheritance14child3_int64_s(ptr noalias sret(%struct.child3_int64_s)
-// LP64-LP64F-LP64D-LABEL: define{{.*}} [2 x i64] @_Z30float_int64_struct_inheritance14child3_int64_s([2 x i64] %a.coerce)
+// LP64-LABEL: define{{.*}} [2 x i64] @_Z30float_int64_struct_inheritance14child3_int64_s([2 x i64] %a.coerce)
+// LP64F-LP64D-LABEL: define{{.*}} { float, i64 } @_Z30float_int64_struct_inheritance14child3_int64_s(float %0, i64 %1)
struct child3_int64_s float_int64_struct_inheritance(struct child3_int64_s a) {
return a;
}
@@ -73,16 +70,54 @@ struct child4_double_s : parent4_double_s {
double d1;
};
-// TODO: Fix incorrect lowering for ilp32d/lp64d ABIs.
-
// ILP32-ILP32F-LABEL: define{{.*}} void @_Z32double_double_struct_inheritance15child4_double_s(ptr noalias sret(%struct.child4_double_s)
-// ILP32D-LABEL: define{{.*}} double @_Z32double_double_struct_inheritance15child4_double_s(double %0)
+// ILP32D-LABEL: define{{.*}} { double, double } @_Z32double_double_struct_inheritance15child4_double_s(double %0, double %1)
// LP64-LP64F-LABEL: define{{.*}} [2 x i64] @_Z32double_double_struct_inheritance15child4_double_s([2 x i64] %a.coerce)
-// LP64D-LABEL: define{{.*}} double @_Z32double_double_struct_inheritance15child4_double_s(double %0)
+// LP64D-LABEL: define{{.*}} { double, double } @_Z32double_double_struct_inheritance15child4_double_s(double %0, double %1)
struct child4_double_s double_double_struct_inheritance(struct child4_double_s a) {
return a;
}
+// When virtual inheritance is used, the resulting struct isn't eligible for
+// passing in registers.
+
+struct parent5_virtual_s {
+ int32_t i1;
+};
+
+struct child5_virtual_s : virtual parent5_virtual_s {
+ float f1;
+};
+
+// ILP32-ILP32F-ILP32D-LABEL: define{{.*}} void @_ZN16child5_virtual_sC1EOS_(ptr noundef nonnull align 4 dereferenceable(8) %this, ptr noundef nonnull align 4 dereferenceable(8) %0)
+// LP64-LP64F-LP64D-LABEL: define{{.*}} void @_ZN16child5_virtual_sC1EOS_(ptr noundef nonnull align 8 dereferenceable(12) %this, ptr noundef nonnull align 8 dereferenceable(12) %0)
+struct child5_virtual_s int32_float_virtual_struct_inheritance(struct child5_virtual_s a) {
+ return a;
+}
+
+// Check for correct lowering in the presence of diamond inheritance.
+
+struct parent6_float_s {
+ float f1;
+};
+
+struct child6a_s : parent6_float_s {
+};
+
+struct child6b_s : parent6_float_s {
+};
+
+struct grandchild_6_s : child6a_s, child6b_s {
+};
+
+// ILP32: define{{.*}} [2 x i32] @_Z38float_float_diamond_struct_inheritance14grandchild_6_s([2 x i32] %a.coerce)
+// ILP32F-ILP64D: define{{.*}} { float, float } @_Z38float_float_diamond_struct_inheritance14grandchild_6_s(float %0, float %1)
+// LP64: define{{.*}} i64 @_Z38float_float_diamond_struct_inheritance14grandchild_6_s(i64 %a.coerce)
+// LP64F-LP64D: define{{.*}} { float, float } @_Z38float_float_diamond_struct_inheritance14grandchild_6_s(float %0, float %1)
+struct grandchild_6_s float_float_diamond_struct_inheritance(struct grandchild_6_s a) {
+ return a;
+}
+
// NOTE: These prefixes are unused. Do not add tests below this line:
// ILP32F: {{.*}}
// LP64F: {{.*}}
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