[llvm] a7137b2 - [BPF] Add support for floats and doubles
Ilya Leoshkevich via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 5 06:11:15 PST 2021
Author: Ilya Leoshkevich
Date: 2021-03-05T15:10:11+01:00
New Revision: a7137b238a07d9399d3ae96c0b461571bd5aa8b2
URL: https://github.com/llvm/llvm-project/commit/a7137b238a07d9399d3ae96c0b461571bd5aa8b2
DIFF: https://github.com/llvm/llvm-project/commit/a7137b238a07d9399d3ae96c0b461571bd5aa8b2.diff
LOG: [BPF] Add support for floats and doubles
Some BPF programs compiled on s390 fail to load, because s390
arch-specific linux headers contain float and double types. At the
moment there is no BTF_KIND for floats and doubles, so the release
version of LLVM ends up emitting type id 0 for them, which the
in-kernel verifier does not accept.
Introduce support for such types to libbpf by representing them using
the new BTF_KIND_FLOAT.
Reviewed By: yonghong-song
Differential Revision: https://reviews.llvm.org/D83289
Added:
llvm/test/CodeGen/BPF/BTF/double.ll
llvm/test/CodeGen/BPF/BTF/float.ll
Modified:
llvm/lib/Target/BPF/BTF.def
llvm/lib/Target/BPF/BTFDebug.cpp
llvm/lib/Target/BPF/BTFDebug.h
Removed:
################################################################################
diff --git a/llvm/lib/Target/BPF/BTF.def b/llvm/lib/Target/BPF/BTF.def
index 2d2e9a04aa6d..66cf2c90ead4 100644
--- a/llvm/lib/Target/BPF/BTF.def
+++ b/llvm/lib/Target/BPF/BTF.def
@@ -30,5 +30,6 @@ HANDLE_BTF_KIND(12, FUNC)
HANDLE_BTF_KIND(13, FUNC_PROTO)
HANDLE_BTF_KIND(14, VAR)
HANDLE_BTF_KIND(15, DATASEC)
+HANDLE_BTF_KIND(16, FLOAT)
#undef HANDLE_BTF_KIND
diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
index f9bdffe7cbae..da7ec32703a5 100644
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -371,6 +371,21 @@ void BTFKindDataSec::emitType(MCStreamer &OS) {
}
}
+BTFTypeFloat::BTFTypeFloat(uint32_t SizeInBits, StringRef TypeName)
+ : Name(TypeName) {
+ Kind = BTF::BTF_KIND_FLOAT;
+ BTFType.Info = Kind << 24;
+ BTFType.Size = roundupToBytes(SizeInBits);
+}
+
+void BTFTypeFloat::completeType(BTFDebug &BDebug) {
+ if (IsCompleted)
+ return;
+ IsCompleted = true;
+
+ BTFType.NameOff = BDebug.addString(Name);
+}
+
uint32_t BTFStringTable::addString(StringRef S) {
// Check whether the string already exists.
for (auto &OffsetM : OffsetToIdMap) {
@@ -409,18 +424,28 @@ uint32_t BTFDebug::addType(std::unique_ptr<BTFTypeBase> TypeEntry) {
}
void BTFDebug::visitBasicType(const DIBasicType *BTy, uint32_t &TypeId) {
- // Only int types are supported in BTF.
+ // Only int and binary floating point types are supported in BTF.
uint32_t Encoding = BTy->getEncoding();
- if (Encoding != dwarf::DW_ATE_boolean && Encoding != dwarf::DW_ATE_signed &&
- Encoding != dwarf::DW_ATE_signed_char &&
- Encoding != dwarf::DW_ATE_unsigned &&
- Encoding != dwarf::DW_ATE_unsigned_char)
+ std::unique_ptr<BTFTypeBase> TypeEntry;
+ switch (Encoding) {
+ case dwarf::DW_ATE_boolean:
+ case dwarf::DW_ATE_signed:
+ case dwarf::DW_ATE_signed_char:
+ case dwarf::DW_ATE_unsigned:
+ case dwarf::DW_ATE_unsigned_char:
+ // Create a BTF type instance for this DIBasicType and put it into
+ // DIToIdMap for cross-type reference check.
+ TypeEntry = std::make_unique<BTFTypeInt>(
+ Encoding, BTy->getSizeInBits(), BTy->getOffsetInBits(), BTy->getName());
+ break;
+ case dwarf::DW_ATE_float:
+ TypeEntry =
+ std::make_unique<BTFTypeFloat>(BTy->getSizeInBits(), BTy->getName());
+ break;
+ default:
return;
+ }
- // Create a BTF type instance for this DIBasicType and put it into
- // DIToIdMap for cross-type reference check.
- auto TypeEntry = std::make_unique<BTFTypeInt>(
- Encoding, BTy->getSizeInBits(), BTy->getOffsetInBits(), BTy->getName());
TypeId = addType(std::move(TypeEntry), BTy);
}
diff --git a/llvm/lib/Target/BPF/BTFDebug.h b/llvm/lib/Target/BPF/BTFDebug.h
index 1bad0d11fee4..fb20ec59574b 100644
--- a/llvm/lib/Target/BPF/BTFDebug.h
+++ b/llvm/lib/Target/BPF/BTFDebug.h
@@ -195,6 +195,15 @@ class BTFKindDataSec : public BTFTypeBase {
void emitType(MCStreamer &OS) override;
};
+/// Handle binary floating point type.
+class BTFTypeFloat : public BTFTypeBase {
+ StringRef Name;
+
+public:
+ BTFTypeFloat(uint32_t SizeInBits, StringRef TypeName);
+ void completeType(BTFDebug &BDebug) override;
+};
+
/// String table.
class BTFStringTable {
/// String table size in bytes.
diff --git a/llvm/test/CodeGen/BPF/BTF/double.ll b/llvm/test/CodeGen/BPF/BTF/double.ll
new file mode 100644
index 000000000000..655c3710d597
--- /dev/null
+++ b/llvm/test/CodeGen/BPF/BTF/double.ll
@@ -0,0 +1,58 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+; double a;
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm t.c
+
+ at a = dso_local local_unnamed_addr global double 0.000000e+00, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK: .section .BTF,"", at progbits
+; CHECK-NEXT: .short 60319 # 0xeb9f
+; CHECK-NEXT: .byte 1
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .long 24
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 52
+; CHECK-NEXT: .long 52
+; CHECK-NEXT: .long 15
+; [1] double, size=8 bytes (64 bits)
+; CHECK-NEXT: .long 1 # BTF_KIND_FLOAT(id = 1)
+; CHECK-NEXT: .long 268435456 # 0x10000000
+; CHECK-NEXT: .long 8
+; [2] a, type=double (1), global
+; CHECK-NEXT: .long 8 # BTF_KIND_VAR(id = 2)
+; CHECK-NEXT: .long 234881024 # 0xe000000
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 1
+; [3] .bss, 1 var, {a, offset=&a, size=8 bytes}
+; CHECK-NEXT: .long 10 # BTF_KIND_DATASEC(id = 3)
+; CHECK-NEXT: .long 251658241 # 0xf000001
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long a
+; CHECK-NEXT: .long 8
+; CHECK-NEXT: .byte 0 # string offset=0
+; CHECK-NEXT: .ascii "double" # string offset=1
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .byte 97 # string offset=8
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .ascii ".bss" # string offset=10
+; CHECK-NEXT: .byte 0
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "double", size: 64, encoding: DW_ATE_float)
+!7 = !{i32 7, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 11.0.0 "}
diff --git a/llvm/test/CodeGen/BPF/BTF/float.ll b/llvm/test/CodeGen/BPF/BTF/float.ll
new file mode 100644
index 000000000000..a061263eed7d
--- /dev/null
+++ b/llvm/test/CodeGen/BPF/BTF/float.ll
@@ -0,0 +1,58 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+; float a;
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm t.c
+
+ at a = dso_local local_unnamed_addr global float 0.000000e+00, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK: .section .BTF,"", at progbits
+; CHECK-NEXT: .short 60319 # 0xeb9f
+; CHECK-NEXT: .byte 1
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .long 24
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 52
+; CHECK-NEXT: .long 52
+; CHECK-NEXT: .long 14
+; [1] float, size=4 bytes (32 bits)
+; CHECK-NEXT: .long 1 # BTF_KIND_FLOAT(id = 1)
+; CHECK-NEXT: .long 268435456 # 0x10000000
+; CHECK-NEXT: .long 4
+; [2] a, type=float (1), global
+; CHECK-NEXT: .long 7 # BTF_KIND_VAR(id = 2)
+; CHECK-NEXT: .long 234881024 # 0xe000000
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 1
+; [3] .bss, 1 var, {a, offset=&a, size=4 bytes}
+; CHECK-NEXT: .long 9 # BTF_KIND_DATASEC(id = 3)
+; CHECK-NEXT: .long 251658241 # 0xf000001
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long a
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .byte 0 # string offset=0
+; CHECK-NEXT: .ascii "float" # string offset=1
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .byte 97 # string offset=7
+; CHECK-NEXT: .byte 0
+; CHECK-NEXT: .ascii ".bss" # string offset=9
+; CHECK-NEXT: .byte 0
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)
+!7 = !{i32 7, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 11.0.0 "}
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