Merging r303679:

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r303679 | oleg | 2017-05-23 15:38:37 -0400 (Tue, 23 May 2017) | 16 lines

[ARM] Temporarily disable globals promotion to constant pools to prevent miscompilation

Summary:
A temporary workaround for PR32780 - rematerialized instructions accessing the same promoted global through different constant pool entries.

The patch turns off the globals promotion optimization leaving all its code in place, so that it can be easily turned on once PR32780 is fixed.

Since this is a miscompilation issue causing generation of misbehaving code, and the problem is very subtle, the patch might be valuable enough to get into 4.0.1.

Reviewers: efriedma, jmolloy

Reviewed By: efriedma

Subscribers: aemerson, javed.absar, llvm-commits, rengolin, asl, tstellar

Differential Revision: https://reviews.llvm.org/D33446
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llvm-svn: 303749

4 files changed, 8 insertions, 8 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 0f84a2359160..da28d85c6190 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -72,7 +72,7 @@ static cl::opt<bool> EnableConstpoolPromotion(
     "arm-promote-constant", cl::Hidden,
     cl::desc("Enable / disable promotion of unnamed_addr constants into "
              "constant pools"),
-    cl::init(true));
+    cl::init(false)); // FIXME: set to true by default once PR32780 is fixed
 static cl::opt<unsigned> ConstpoolPromotionMaxSize(
     "arm-promote-constant-max-size", cl::Hidden,
     cl::desc("Maximum size of constant to promote into a constant pool"),
diff --git a/llvm/test/CodeGen/ARM/constantpool-promote-dbg.ll b/llvm/test/CodeGen/ARM/constantpool-promote-dbg.ll
index ae765d26dcac..84386d2975f0 100644
--- a/llvm/test/CodeGen/ARM/constantpool-promote-dbg.ll
+++ b/llvm/test/CodeGen/ARM/constantpool-promote-dbg.ll
@@ -1,4 +1,4 @@
-; RUN: llc -relocation-model=static < %s | FileCheck %s
+; RUN: llc -relocation-model=static -arm-promote-constant < %s | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "thumbv7m--linux-gnu"
diff --git a/llvm/test/CodeGen/ARM/constantpool-promote-ldrh.ll b/llvm/test/CodeGen/ARM/constantpool-promote-ldrh.ll
index 9e369dc08c4b..59970495874b 100644
--- a/llvm/test/CodeGen/ARM/constantpool-promote-ldrh.ll
+++ b/llvm/test/CodeGen/ARM/constantpool-promote-ldrh.ll
@@ -1,5 +1,5 @@
-; RUN: llc < %s -O0 -fast-isel=false | FileCheck %s
-; RUN: llc < %s -O0 -fast-isel=false -filetype=obj
+; RUN: llc < %s -O0 -fast-isel=false -arm-promote-constant | FileCheck %s
+; RUN: llc < %s -O0 -fast-isel=false -filetype=obj -arm-promote-constant
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "thumbv6m-arm-linux-gnueabi"
 
diff --git a/llvm/test/CodeGen/ARM/constantpool-promote.ll b/llvm/test/CodeGen/ARM/constantpool-promote.ll
index fb1bdfd62fb7..d1ff602b783f 100644
--- a/llvm/test/CodeGen/ARM/constantpool-promote.ll
+++ b/llvm/test/CodeGen/ARM/constantpool-promote.ll
@@ -1,7 +1,7 @@
-; RUN: llc -relocation-model=static < %s | FileCheck %s
-; RUN: llc -relocation-model=pic < %s | FileCheck %s
-; RUN: llc -relocation-model=ropi < %s | FileCheck %s
-; RUN: llc -relocation-model=rwpi < %s | FileCheck %s
+; RUN: llc -relocation-model=static -arm-promote-constant < %s | FileCheck %s
+; RUN: llc -relocation-model=pic -arm-promote-constant < %s | FileCheck %s
+; RUN: llc -relocation-model=ropi -arm-promote-constant < %s | FileCheck %s
+; RUN: llc -relocation-model=rwpi -arm-promote-constant < %s | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64"
 target triple = "armv7--linux-gnueabihf"