Remove explicit setting of the CFI jumptable section name.

[dmikulin]

Summary

Remove explicit setting of the CFI jumptable section name, it does not appear to be needed: jump table sections are created with .cfi.jumptable suffix. With this change each jump table is placed in a separate section, which allows the linker to re-order them.

[pcc]

LGTM

llvm/test/Transforms/LowerTypeTests/function-arm-thumb.ll

34

Nit: I'd drop the {{.*}} here and in function.ll, as they don't appear to be needed.

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

void LowerTypeTestsModule::createJumpTable(
   AsmArgs.reserve(Functions.size() * 2);
 
   Triple::ArchType JumpTableArch = selectJumpTableArmEncoding(Functions, Arch);
 
   for (unsigned I = 0; I != Functions.size(); ++I)
     createJumpTableEntry(AsmOS, ConstraintOS, JumpTableArch, AsmArgs,
                          cast<Function>(Functions[I]->getGlobal()));
 
-  // Try to emit the jump table at the end of the text segment.
-  // Jump table must come after __cfi_check in the cross-dso mode.
-  // FIXME: this magic section name seems to do the trick.
-  F->setSection(ObjectFormat == Triple::MachO
-                    ? "__TEXT,__text,regular,pure_instructions"
-                    : ".text.cfi");
   // Align the whole table by entry size.
   F->setAlignment(getJumpTableEntrySize());
   // Skip prologue.
   // Disabled on win32 due to https://llvm.org/bugs/show_bug.cgi?id=28641#c3.
   // Luckily, this function does not get any prologue even without the
   // attribute.
   if (OS != Triple::Win32)
     F->addFnAttr(Attribute::Naked);

llvm/test/Transforms/LowerTypeTests/function-arm-thumb.ll

 
 define void @h2() "target-features"="-thumb-mode" !type !1 {
   ret void
 }
 
 !0 = !{i32 0, !"typeid1"}
 !1 = !{i32 0, !"typeid2"}
 
-; CHECK: define private void {{.*}} #[[AT:.*]] section ".text.cfi" align 4 {
+; CHECK: define private void {{.*}} #[[AT:.*]] {{.*}}align 4 {
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:  call void asm sideeffect "b.w $0\0Ab.w $1\0A", "s,s"(void ()* @f1.cfi, void ()* @g1.cfi)
 ; CHECK-NEXT:  unreachable
 ; CHECK-NEXT: }
 
-; CHECK: define private void {{.*}} #[[AA:.*]] section ".text.cfi" align 4 {
+; CHECK: define private void {{.*}} #[[AA:.*]] {{.*}}align 4 {
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:  call void asm sideeffect "b $0\0Ab $1\0Ab $2\0A", "s,s,s"(void ()* @f2.cfi, void ()* @g2.cfi, void ()* @h2.cfi)
 ; CHECK-NEXT:  unreachable
 ; CHECK-NEXT: }
 
 ; CHECK-DAG: attributes #[[AA]] = { naked nounwind "target-features"="-thumb-mode" }
 ; CHECK-DAG: attributes #[[AT]] = { naked nounwind "target-cpu"="cortex-a8" "target-features"="+thumb-mode" }

llvm/test/Transforms/LowerTypeTests/function-disjoint.ll

define i1 @foo(i8* %p) {
   %x = call i1 @llvm.type.test(i8* %p, metadata !"typeid1")
   ; X64: icmp eq i64 {{.*}}, ptrtoint (void ()* @[[JT1]] to i64)
   ; WASM32: icmp eq i64 {{.*}}, mul (i64 ptrtoint (i8* getelementptr (i8, i8* null, i32 1) to i64), i64 2)
   %y = call i1 @llvm.type.test(i8* %p, metadata !"typeid2")
   %z = add i1 %x, %y
   ret i1 %z
 }
 
-; X64: define private void @[[JT0]]() #{{.*}} section ".text.cfi" align 8 {
+; X64: define private void @[[JT0]]() #{{.*}} align 8 {
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(void ()* @f.cfi)
 
-; X64: define private void @[[JT1]]() #{{.*}} section ".text.cfi" align 8 {
+; X64: define private void @[[JT1]]() #{{.*}} align 8 {
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(void ()* @g.cfi)
 
 ; WASM32: ![[I0]] = !{i64 1}
 ; WASM32: ![[I1]] = !{i64 2}

llvm/test/Transforms/LowerTypeTests/function-ext.ll

 }
 
 declare i1 @llvm.type.test(i8* %ptr, metadata %bitset) nounwind readnone
 
 !0 = !{i64 0, !"void"}
 ; WASM-NOT: !{i64 0}
 ; WASM-NOT: !{i64 1}
 
-; X64: define private void @[[JT]]() #{{.*}} section ".text.cfi" align {{.*}} {
+; X64: define private void @[[JT]]() #{{.*}} align {{.*}} {
 ; X64:   call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s"(void ()* @foo)

llvm/test/Transforms/LowerTypeTests/function-weak.ll

 
 declare i1 @llvm.type.test(i8* %ptr, metadata %bitset) nounwind readnone
 
 define i1 @foo(i8* %p) {
   %x = call i1 @llvm.type.test(i8* %p, metadata !"typeid1")
   ret i1 %x
 }
 
-; X86: define private void @[[JT]]() #{{.*}} section ".text.cfi" align 8 {
-; ARM: define private void @[[JT]]() #{{.*}} section ".text.cfi" align 4 {
+; X86: define private void @[[JT]]() #{{.*}} align 8 {
+; ARM: define private void @[[JT]]() #{{.*}} align 4 {
 
 ; CHECK: define internal void @__cfi_global_var_init() section ".text.startup" {
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT: store { void ()*, void ()*, i32 } { void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null), void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null), i32 42 }, { void ()*, void ()*, i32 }* @s, align 8
 ; CHECK-NEXT: store void ()* bitcast (i8* getelementptr (i8, i8* bitcast (void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null) to i8*), i64 42) to void ()*), void ()** @x4, align 8
 ; CHECK-NEXT: store void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null), void ()** @x3, align 8
 ; CHECK-NEXT: store void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null), void ()** @x2, align 8
 ; CHECK-NEXT: store void ()* select (i1 icmp ne (void ()* @f, void ()* null), void ()* @[[JT]], void ()* null), void ()** @x, align 8
 ; CHECK-NEXT: ret void
 ; CHECK-NEXT: }
 
 !0 = !{i32 0, !"typeid1"}

llvm/test/Transforms/LowerTypeTests/function.ll

 define i1 @foo(i8* %p) {
   ; NATIVE: sub i64 {{.*}}, ptrtoint (void ()* @[[JT]] to i64)
   ; WASM32: sub i64 {{.*}}, ptrtoint (i8* getelementptr (i8, i8* null, i64 1) to i64)
   ; WASM32: icmp ule i64 {{.*}}, 1
   %x = call i1 @llvm.type.test(i8* %p, metadata !"typeid1")
   ret i1 %x
 }
 
-; X86-LINUX:   define private void @[[JT]]() #[[ATTR:.*]] section ".text.cfi" align 8 {
-; X86-WIN32:   define private void @[[JT]]() #[[ATTR:.*]] section ".text.cfi" align 8 {
-; ARM:   define private void @[[JT]]() #[[ATTR:.*]] section ".text.cfi" align 4 {
-; THUMB: define private void @[[JT]]() #[[ATTR:.*]] section ".text.cfi" align 4 {
+; X86-LINUX:   define private void @[[JT]]() #[[ATTR:.*]] {{.*}}align 8 {
+; X86-WIN32:   define private void @[[JT]]() #[[ATTR:.*]] {{.*}}align 8 {
+; ARM:   define private void @[[JT]]() #[[ATTR:.*]] {{.*}}align 4 {
+; THUMB: define private void @[[JT]]() #[[ATTR:.*]] {{.*}}align 4 {
 
 ; X86:      jmp ${0:c}@plt
 ; X86-SAME: int3
 ; X86-SAME: int3
 ; X86-SAME: int3
 ; X86-SAME: jmp ${1:c}@plt
 ; X86-SAME: int3
 ; X86-SAME: int3

llvm/test/Transforms/LowerTypeTests/section.ll

 }
 
 define i1 @g() {
 entry:
   %0 = call i1 @llvm.type.test(i8* bitcast (void ()* @f to i8*), metadata !"_ZTSFvE")
   ret i1 %0
 }
 
-; CHECK: define private void @[[JT]]() #{{.*}} section ".text.cfi" align {{.*}} {
+; CHECK: define private void @[[JT]]() #{{.*}} align {{.*}} {
 
 declare i1 @llvm.type.test(i8*, metadata) nounwind readnone
 
 !0 = !{i64 0, !"_ZTSFvE"}