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/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 980de9a..af3db51 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -3836,6 +3836,51 @@
writeOperand(II->getNormalDest(), true);
Out << " unwind ";
writeOperand(II->getUnwindDest(), true);
+ } else if (const CallBrInst *CBI = dyn_cast<CallBrInst>(&I)) {
+ Operand = CBI->getCalledValue();
+ FunctionType *FTy = CBI->getFunctionType();
+ Type *RetTy = FTy->getReturnType();
+ const AttributeList &PAL = CBI->getAttributes();
+
+ // Print the calling convention being used.
+ if (CBI->getCallingConv() != CallingConv::C) {
+ Out << " ";
+ PrintCallingConv(CBI->getCallingConv(), Out);
+ }
+
+ if (PAL.hasAttributes(AttributeList::ReturnIndex))
+ Out << ' ' << PAL.getAsString(AttributeList::ReturnIndex);
+
+ // If possible, print out the short form of the callbr instruction. We can
+ // only do this if the first argument is a pointer to a nonvararg function,
+ // and if the return type is not a pointer to a function.
+ //
+ Out << ' ';
+ TypePrinter.print(FTy->isVarArg() ? FTy : RetTy, Out);
+ Out << ' ';
+ writeOperand(Operand, false);
+ Out << '(';
+ for (unsigned op = 0, Eop = CBI->getNumArgOperands(); op < Eop; ++op) {
+ if (op)
+ Out << ", ";
+ writeParamOperand(CBI->getArgOperand(op), PAL.getParamAttributes(op));
+ }
+
+ Out << ')';
+ if (PAL.hasAttributes(AttributeList::FunctionIndex))
+ Out << " #" << Machine.getAttributeGroupSlot(PAL.getFnAttributes());
+
+ writeOperandBundles(CBI);
+
+ Out << "\n to ";
+ writeOperand(CBI->getDefaultDest(), true);
+ Out << " [";
+ for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i) {
+ if (i != 0)
+ Out << ", ";
+ writeOperand(CBI->getIndirectDest(i), true);
+ }
+ Out << ']';
} else if (const AllocaInst *AI = dyn_cast<AllocaInst>(&I)) {
Out << ' ';
if (AI->isUsedWithInAlloca())