Pull in r241142 from upstream llvm trunk (by David Majnemer):

  [SCCP] Turn loads of null into undef instead of zero initialized values

  Surprisingly, this is a correctness issue: the mmx type exists for
  calling convention purposes, LLVM doesn't have a zero representation for
  them.

  This partially fixes PR23999.

Pull in r241143 from upstream llvm trunk (by David Majnemer):

  [LoopUnroll] Use undef for phis with no value live

  We would create a phi node with a zero initialized operand instead of
  undef in the case where no value was originally available.  This was
  problematic for x86_mmx which has no null value.

These fix a "Cannot create a null constant of that type!" error when
compiling the graphics/sdl2_gfx port with MMX enabled.

Reported by:	amdmi3

2 files changed, 2 insertions, 2 deletions

diff --git a/contrib/llvm/lib/Transforms/Scalar/SCCP.cpp b/contrib/llvm/lib/Transforms/Scalar/SCCP.cpp
index cfc9a8e..e0e314a 100644
--- a/contrib/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/contrib/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1054,7 +1054,7 @@ void SCCPSolver::visitLoadInst(LoadInst &I) {
 
   // load null -> null
   if (isa<ConstantPointerNull>(Ptr) && I.getPointerAddressSpace() == 0)
-    return markConstant(IV, &I, Constant::getNullValue(I.getType()));
+    return markConstant(IV, &I, UndefValue::get(I.getType()));
 
   // Transform load (constant global) into the value loaded.
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
diff --git a/contrib/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp b/contrib/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
index 8a32215..db4a5c1 100644
--- a/contrib/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
@@ -81,7 +81,7 @@ static void ConnectProlog(Loop *L, Value *BECount, unsigned Count,
       if (L->contains(PN)) {
         NewPN->addIncoming(PN->getIncomingValueForBlock(NewPH), OrigPH);
       } else {
-        NewPN->addIncoming(Constant::getNullValue(PN->getType()), OrigPH);
+        NewPN->addIncoming(UndefValue::get(PN->getType()), OrigPH);
       }
 
       Value *V = PN->getIncomingValueForBlock(Latch);