From 9d812a2805161665d56a78734da98b58f39ce0fc Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Sat, 2 Jul 2011 07:17:37 +0000
Subject: [PATCH] Better diagnostics when inline asm fails to allocate.

asm.c:2:7: error: ran out of registers during register allocation
  asm(""::"r"(0), "r"(1), "r"(2), "r"(3), "r"(4), "r"(5), "r"(6), "r"(7), "r"(8), "r"(9));
        ^

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134310 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/RegAllocBasic.cpp        | 26 ++++++++++++++------------
 lib/CodeGen/RegAllocFast.cpp         | 14 ++++----------
 test/CodeGen/X86/inline-asm-error.ll |  6 ++----
 3 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp
index bcb38d7c35a..5ea26adc764 100644
--- a/lib/CodeGen/RegAllocBasic.cpp
+++ b/lib/CodeGen/RegAllocBasic.cpp
@@ -324,19 +324,21 @@ void RegAllocBase::allocatePhysRegs() {
 
     if (AvailablePhysReg == ~0u) {
       // selectOrSplit failed to find a register!
-      std::string msg;
-      raw_string_ostream Msg(msg);
-      Msg << "Ran out of registers during register allocation!"
-             "\nCannot allocate: " << *VirtReg;
+      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);
-      MachineInstr *MI = I.skipInstruction();) {
-        if (!MI->isInlineAsm())
-          continue;
-        Msg << "\nPlease check your inline asm statement for "
-          "invalid constraints:\n";
-        MI->print(Msg, &VRM->getMachineFunction().getTarget());
-      }
-      report_fatal_error(Msg.str());
+           (MI = I.skipInstruction());)
+        if (MI->isInlineAsm())
+          break;
+      if (MI)
+        MI->emitError(Msg);
+      else
+        report_fatal_error(Msg);
+      // Keep going after reporting the error.
+      VRM->assignVirt2Phys(VirtReg->reg,
+                 RegClassInfo.getOrder(MRI->getRegClass(VirtReg->reg)).front());
+      continue;
     }
 
     if (AvailablePhysReg)
diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index ee23194c058..b36a445291b 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -530,16 +530,10 @@ void RAFast::allocVirtReg(MachineInstr *MI, LiveRegEntry &LRE, unsigned Hint) {
     return assignVirtToPhysReg(LRE, BestReg);
   }
 
-  // Nothing we can do.
-  std::string msg;
-  raw_string_ostream Msg(msg);
-  Msg << "Ran out of registers during register allocation!";
-  if (MI->isInlineAsm()) {
-    Msg << "\nPlease check your inline asm statement for "
-        << "invalid constraints:\n";
-    MI->print(Msg, TM);
-  }
-  report_fatal_error(Msg.str());
+  // Nothing we can do. Report an error and keep going with a bad allocation.
+  MI->emitError("ran out of registers during register allocation");
+  definePhysReg(MI, *AO.begin(), regFree);
+  assignVirtToPhysReg(LRE, *AO.begin());
 }
 
 /// defineVirtReg - Allocate a register for VirtReg and mark it as dirty.
diff --git a/test/CodeGen/X86/inline-asm-error.ll b/test/CodeGen/X86/inline-asm-error.ll
index 29c5ae51cf8..134d6e95283 100644
--- a/test/CodeGen/X86/inline-asm-error.ll
+++ b/test/CodeGen/X86/inline-asm-error.ll
@@ -5,10 +5,8 @@
 ; RUN: FileCheck %s < %t2
 ; RUN: FileCheck %s < %t3
 
-; The register allocator must fail on this function, and it should print the
-; inline asm in the diagnostic.
-; CHECK: LLVM ERROR: Ran out of registers during register allocation!
-; CHECK: INLINEASM <es:hello world>
+; The register allocator must fail on this function.
+; CHECK: error: ran out of registers during register allocation
 
 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: