Use the MachineBasicBlock symbol for a callbr target

Summary:
Inline asm doesn't use labels when compiled as an object file. Therefore, we
shouldn't create one for the (potential) callbr destination. Instead, use the
symbol for the MachineBasicBlock.

Reviewers: nickdesaulniers, craig.topper

Reviewed By: nickdesaulniers

Subscribers: xbolva00, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64888

llvm-svn: 366523

Author: isanbard

llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp

@@ -430,8 +430,13 @@ static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
           if (Modifier[0] == 'l') { // Labels are target independent.
             if (MI->getOperand(OpNo).isBlockAddress()) {
               const BlockAddress *BA = MI->getOperand(OpNo).getBlockAddress();
-              MCSymbol *Sym = AP->GetBlockAddressSymbol(BA);
-              Sym->print(OS, AP->MAI);
+              const BasicBlock *BB = BA->getBasicBlock();
+              const MachineFunction *MF = MI->getParent()->getParent();
+              for (const MachineBasicBlock &MBB : *MF)
+                if (BB == MBB.getBasicBlock()) {
+                  MBB.getSymbol()->print(OS, AP->MAI);
+                  break;
+                }
             } else if (MI->getOperand(OpNo).isMBB()) {
               const MCSymbol *Sym = MI->getOperand(OpNo).getMBB()->getSymbol();
               Sym->print(OS, AP->MAI);

llvm/test/CodeGen/X86/callbr-asm-obj-file.ll

@@ -0,0 +1,19 @@
+; RUN: llc < %s -mtriple=x86_64-linux-gnu -filetype=obj -o - \
+; RUN:  | llvm-objdump -triple x86_64-linux-gnu -d - \
+; RUN:  | FileCheck %s
+
+; CHECK: 0000000000000000 test1:
+; CHECK-NEXT:   0: 74 00 je 0 <test1+0x2>
+; CHECK-NEXT:   2: c3    retq
+
+define void @test1() {
+entry:
+  callbr void asm sideeffect "je ${0:l}", "X,~{dirflag},~{fpsr},~{flags}"(i8* blockaddress(@test1, %a.b.normal.jump))
+          to label %asm.fallthrough [label %a.b.normal.jump]
+
+asm.fallthrough:
+  ret void
+
+a.b.normal.jump:
+  ret void
+}

llvm/test/CodeGen/X86/callbr-asm.ll

@@ -12,7 +12,7 @@ define i32 @test1(i32 %a) {
 ; CHECK-NEXT:    addl $4, %eax
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:    jmp .Ltmp00
+; CHECK-NEXT:    jmp .LBB0_2
 ; CHECK-NEXT:    #NO_APP
 ; CHECK-NEXT:  .LBB0_1: # %normal
 ; CHECK-NEXT:    xorl %eax, %eax
@@ -87,17 +87,17 @@ define dso_local i32 @test3(i32 %a) {
 ; CHECK-NEXT:    # Parent Loop BB2_3 Depth=3
 ; CHECK-NEXT:    # => This Inner Loop Header: Depth=4
 ; CHECK-NEXT:    #APP
-; CHECK-NEXT:    jmp .Ltmp10
-; CHECK-NEXT:    jmp .Ltmp20
-; CHECK-NEXT:    jmp .Ltmp30
+; CHECK-NEXT:    jmp .LBB2_1
+; CHECK-NEXT:    jmp .LBB2_2
+; CHECK-NEXT:    jmp .LBB2_3
 ; CHECK-NEXT:    #NO_APP
 ; CHECK-NEXT:  .LBB2_5: # %normal0
 ; CHECK-NEXT:    # in Loop: Header=BB2_4 Depth=4
 ; CHECK-NEXT:    #APP
-; CHECK-NEXT:    jmp .Ltmp10
-; CHECK-NEXT:    jmp .Ltmp20
-; CHECK-NEXT:    jmp .Ltmp30
-; CHECK-NEXT:    jmp .Ltmp40
+; CHECK-NEXT:    jmp .LBB2_1
+; CHECK-NEXT:    jmp .LBB2_2
+; CHECK-NEXT:    jmp .LBB2_3
+; CHECK-NEXT:    jmp .LBB2_4
 ; CHECK-NEXT:    #NO_APP
 ; CHECK-NEXT:  .LBB2_6: # %normal1
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax