From b41932d54e590b3ce95d9fddd81046f682ee724d Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Sat, 4 Jul 2015 20:09:24 +0000
Subject: [PATCH] Add llvm patch corresponding to r285149.

---
 ...tch-10-llvm-r241142-r241143-mmx-undef.diff | 88 +++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 contrib/llvm/patches/patch-10-llvm-r241142-r241143-mmx-undef.diff

diff --git a/contrib/llvm/patches/patch-10-llvm-r241142-r241143-mmx-undef.diff b/contrib/llvm/patches/patch-10-llvm-r241142-r241143-mmx-undef.diff
new file mode 100644
index 000000000000..1750e7438954
--- /dev/null
+++ b/contrib/llvm/patches/patch-10-llvm-r241142-r241143-mmx-undef.diff
@@ -0,0 +1,88 @@
+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.
+
+Introduced here: http://svnweb.freebsd.org/changeset/base/285149
+
+Index: lib/Transforms/Scalar/SCCP.cpp
+===================================================================
+--- lib/Transforms/Scalar/SCCP.cpp
++++ lib/Transforms/Scalar/SCCP.cpp
+@@ -1054,7 +1054,7 @@
+ 
+   // 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)) {
+Index: lib/Transforms/Utils/LoopUnrollRuntime.cpp
+===================================================================
+--- lib/Transforms/Utils/LoopUnrollRuntime.cpp
++++ lib/Transforms/Utils/LoopUnrollRuntime.cpp
+@@ -81,7 +81,7 @@
+       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);
+Index: test/Transforms/LoopUnroll/X86/mmx.ll
+===================================================================
+--- test/Transforms/LoopUnroll/X86/mmx.ll
++++ test/Transforms/LoopUnroll/X86/mmx.ll
+@@ -0,0 +1,21 @@
++; RUN: opt < %s -S -loop-unroll | FileCheck %s
++target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
++target triple = "x86_64-unknown-linux-gnu"
++
++define x86_mmx @f() #0 {
++entry:
++  br label %for.body
++
++for.body:                                         ; preds = %for.body, %entry
++  %phi = phi i32 [ 1, %entry ], [ %add, %for.body ]
++  %add = add i32 %phi, 1
++  %cmp = icmp eq i32 %phi, 0
++  br i1 %cmp, label %exit, label %for.body
++
++exit:                                             ; preds = %for.body
++  %ret = phi x86_mmx [ undef, %for.body ]
++  ; CHECK: ret x86_mmx %ret
++  ret x86_mmx %ret
++}
++
++attributes #0 = { "target-cpu"="x86-64" }
+Index: test/Transforms/SCCP/crash.ll
+===================================================================
+--- test/Transforms/SCCP/crash.ll
++++ test/Transforms/SCCP/crash.ll
+@@ -27,3 +27,8 @@
+   %B = extractvalue [4 x i32] %A, 1
+   ret i32 %B
+ }
++
++define x86_mmx @test3() {
++  %load = load x86_mmx* null
++  ret x86_mmx %load
++}