[llvm] r192041 - Emit a better error when running out of registers on inline asm.

[Benjamin Kramer]

Author: d0k
Date: Sat Oct  5 14:33:37 2013
New Revision: 192041

URL: http://llvm.org/viewvc/llvm-project?rev=192041&view=rev
Log:
Emit a better error when running out of registers on inline asm.

The most likely case where this error happens is when the user specifies
too many register operands. Don't make it look like an internal LLVM bug
when we can see that the error is coming from an inline asm instruction.
For other instructions we keep the "ran out of registers" error.

Modified:
    llvm/trunk/lib/CodeGen/RegAllocBase.cpp
    llvm/trunk/lib/CodeGen/RegAllocFast.cpp
    llvm/trunk/test/CodeGen/X86/inline-asm-error.ll

Modified: llvm/trunk/lib/CodeGen/RegAllocBase.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocBase.cpp?rev=192041&r1=192040&r2=192041&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocBase.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocBase.cpp Sat Oct  5 14:33:37 2013
@@ -106,7 +106,6 @@ void RegAllocBase::allocatePhysRegs() {
 
     if (AvailablePhysReg == ~0u) {
       // selectOrSplit failed to find a register!
-      const char *Msg = "ran out of registers during register allocation";
       // Probably caused by an inline asm.
       MachineInstr *MI;
       for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(VirtReg->reg);
@@ -114,9 +113,9 @@ void RegAllocBase::allocatePhysRegs() {
         if (MI->isInlineAsm())
           break;
       if (MI)
-        MI->emitError(Msg);
+        MI->emitError("inline assembly requires more registers than available");
       else
-        report_fatal_error(Msg);
+        report_fatal_error("ran out of registers during register allocation");
       // Keep going after reporting the error.
       VRM->assignVirt2Phys(VirtReg->reg,
                  RegClassInfo.getOrder(MRI->getRegClass(VirtReg->reg)).front());

Modified: llvm/trunk/lib/CodeGen/RegAllocFast.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocFast.cpp?rev=192041&r1=192040&r2=192041&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocFast.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocFast.cpp Sat Oct  5 14:33:37 2013
@@ -569,7 +569,10 @@ RAFast::LiveRegMap::iterator RAFast::all
   }
 
   // Nothing we can do. Report an error and keep going with a bad allocation.
-  MI->emitError("ran out of registers during register allocation");
+  if (MI->isInlineAsm())
+    MI->emitError("inline assembly requires more registers than available");
+  else
+    MI->emitError("ran out of registers during register allocation");
   definePhysReg(MI, *AO.begin(), regFree);
   return assignVirtToPhysReg(VirtReg, *AO.begin());
 }

Modified: llvm/trunk/test/CodeGen/X86/inline-asm-error.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/inline-asm-error.ll?rev=192041&r1=192040&r2=192041&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/inline-asm-error.ll (original)
+++ llvm/trunk/test/CodeGen/X86/inline-asm-error.ll Sat Oct  5 14:33:37 2013
@@ -6,7 +6,7 @@
 ; RUN: FileCheck %s < %t3
 
 ; The register allocator must fail on this function.
-; CHECK: error: ran out of registers during register allocation
+; CHECK: error: inline assembly requires more registers than available
 
 define void @f(i32 %x0, i32 %x1, i32 %x2, i32 %x3, i32 %x4, i32 %x5, i32 %x6, i32 %x7, i32 %x8, i32 %x9) nounwind ssp {
 entry: