Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html
This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.
This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.
There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.
Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii
Differential Revision: https://reviews.llvm.org/D53765
llvm-svn: 353563
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index 9e6d35c..52acabe 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -433,9 +433,16 @@
++OpNo; // Skip over the ID number.
if (Modifier[0] == 'l') { // Labels are target independent.
- // FIXME: What if the operand isn't an MBB, report error?
- const MCSymbol *Sym = MI->getOperand(OpNo).getMBB()->getSymbol();
- Sym->print(OS, AP->MAI);
+ if (MI->getOperand(OpNo).isBlockAddress()) {
+ const BlockAddress *BA = MI->getOperand(OpNo).getBlockAddress();
+ MCSymbol *Sym = AP->GetBlockAddressSymbol(BA);
+ Sym->print(OS, AP->MAI);
+ } else if (MI->getOperand(OpNo).isMBB()) {
+ const MCSymbol *Sym = MI->getOperand(OpNo).getMBB()->getSymbol();
+ Sym->print(OS, AP->MAI);
+ } else {
+ Error = true;
+ }
} else {
if (InlineAsm::isMemKind(OpFlags)) {
Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,