From ab3cb5cf1bc3f6729503f66f81b87002c7697c02 Mon Sep 17 00:00:00 2001
From: Reed Kotler <rkotler@mips.com>
Date: Sun, 24 Nov 2013 02:53:09 +0000
Subject: [PATCH] Fix a funny bug I introduced during conversion of ARM
 constant islands to Mips. I had to move some code and I moved a declaration
 forward past it's first use in the function but by nutty coincidence there
 was another variable of the same name and type and  with completely unrelated
 function that was declared globally in the class so no compilation error
 ensued. It required some unusual conditions for it to even matter. Caused
 test case casts.c in test-suite to fail during compilation with a duplicate
 symbol error. I would have noticed it during final code review for this port.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195565 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsConstantIslandPass.cpp |  8 +++--
 test/CodeGen/Mips/ci2.ll                   | 39 ++++++++++++++++++++++
 2 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 test/CodeGen/Mips/ci2.ll

diff --git a/lib/Target/Mips/MipsConstantIslandPass.cpp b/lib/Target/Mips/MipsConstantIslandPass.cpp
index 63d07f35478..f3a61e84cb7 100644
--- a/lib/Target/Mips/MipsConstantIslandPass.cpp
+++ b/lib/Target/Mips/MipsConstantIslandPass.cpp
@@ -1275,6 +1275,10 @@ bool MipsConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) {
   // Decrement the old entry, and remove it if refcount becomes 0.
   decrementCPEReferenceCount(CPI, CPEMI);
 
+  // No existing clone of this CPE is within range.
+  // We will be generating a new clone.  Get a UID for it.
+  unsigned ID = createPICLabelUId();
+
   // Now that we have an island to add the CPE to, clone the original CPE and
   // add it to the island.
   U.HighWaterMark = NewIsland;
@@ -1290,9 +1294,7 @@ bool MipsConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) {
   BBInfo[NewIsland->getNumber()].Size += Size;
   adjustBBOffsetsAfter(llvm::prior(MachineFunction::iterator(NewIsland)));
 
-  // No existing clone of this CPE is within range.
-  // We will be generating a new clone.  Get a UID for it.
-  unsigned ID = createPICLabelUId();
+
 
   // Finally, change the CPI in the instruction operand to be ID.
   for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i)
diff --git a/test/CodeGen/Mips/ci2.ll b/test/CodeGen/Mips/ci2.ll
new file mode 100644
index 00000000000..7187f0c7588
--- /dev/null
+++ b/test/CodeGen/Mips/ci2.ll
@@ -0,0 +1,39 @@
+; RUN: llc -mtriple=mipsel-linux-gnu -march=mipsel -mcpu=mips16 -soft-float -mips16-hard-float -relocation-model=static -mips16-constant-islands   < %s | FileCheck %s -check-prefix=constisle
+
+@i = common global i32 0, align 4
+@b = common global i32 0, align 4
+@l = common global i32 0, align 4
+
+; Function Attrs: nounwind
+define void @foo() #0 {
+entry:
+  store i32 305419896, i32* @i, align 4
+  %0 = load i32* @b, align 4
+  %tobool = icmp ne i32 %0, 0
+  br i1 %tobool, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  store i32 10, i32* @b, align 4
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  store i32 20, i32* @b, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  call void asm sideeffect ".space 100000", ""() #1, !srcloc !1
+  store i32 305419896, i32* @l, align 4
+  ret void
+; constisle: $CPI0_1:
+; constisle	.4byte	305419896               # 0x12345678
+; constisle	#APP
+; constisle	.space 100000
+; constisle	#NO_APP
+; constisle $CPI0_0:
+; constisle	.4byte	305419896               # 0x12345678
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind }
+
+!1 = metadata !{i32 103}