Merging r168320: into 3.2 relase branch.

Handle mixed normal and early-clobber defs on inline asm.

PR14376.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168527 91177308-0d34-0410-b5e6-96231b3b80d8

Author: 32bitmicro

lib/CodeGen/LiveInterval.cpp

@@ -59,8 +59,16 @@ VNInfo *LiveInterval::createDeadDef(SlotIndex Def,
     return VNI;
   }
   if (SlotIndex::isSameInstr(Def, I->start)) {
-    assert(I->start == Def && "Cannot insert def, already live");
-    assert(I->valno->def == Def && "Inconsistent existing value def");
+    assert(I->valno->def == I->start && "Inconsistent existing value def");
+
+    // It is possible to have both normal and early-clobber defs of the same
+    // register on an instruction. It doesn't make a lot of sense, but it is
+    // possible to specify in inline assembly.
+    //
+    // Just convert everything to early-clobber.
+    Def = std::min(Def, I->start);
+    if (Def != I->start)
+      I->start = I->valno->def = Def;
     return I->valno;
   }
   assert(SlotIndex::isEarlierInstr(Def, I->start) && "Already live at def");

test/CodeGen/X86/inline-asm.ll

@@ -52,3 +52,10 @@ entry:
   %0 = call { i32, i32, i32, i32, i32 } asm sideeffect "", "=&r,=&r,=&r,=&r,=&q,r,~{ecx},~{memory},~{dirflag},~{fpsr},~{flags}"(i8* %h) nounwind
   ret void
 }
+
+; Mix normal and EC defs of the same register.
+define i32 @pr14376() nounwind noinline {
+entry:
+  %asm = tail call i32 asm sideeffect "", "={ax},i,~{eax},~{flags},~{rax}"(i64 61) nounwind
+  ret i32 %asm
+}