From cc7052343e5e955d4e2f48885c06360f9003390a Mon Sep 17 00:00:00 2001
From: Bob Wilson <bob.wilson@apple.com>
Date: Fri, 15 Nov 2013 19:09:27 +0000
Subject: Avoid illegal integer promotion in fastisel

Stop folding constant adds into GEP when the type size doesn't match.
Otherwise, the adds' operands are effectively being promoted, changing the
conditions of an overflow.  Results are different when:

    sext(a) + sext(b) != sext(a + b)

Problem originally found on x86-64, but also fixed issues with ARM and PPC,
which used similar code.

<rdar://problem/15292280>

Patch by Duncan Exon Smith!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194840 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMFastISel.cpp     | 9 ++-------
 lib/Target/PowerPC/PPCFastISel.cpp | 9 ++-------
 lib/Target/X86/X86FastISel.cpp     | 9 ++-------
 3 files changed, 6 insertions(+), 21 deletions(-)

(limited to 'lib/Target')

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index f3a74c7..a4004f3 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -900,13 +900,8 @@ bool ARMFastISel::ARMComputeAddress(const Value *Obj, Address &Addr) {
               TmpOffset += CI->getSExtValue() * S;
               break;
             }
-            if (isa<AddOperator>(Op) &&
-                (!isa<Instruction>(Op) ||
-                 FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-                 == FuncInfo.MBB) &&
-                isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-              // An add (in the same block) with a constant operand. Fold the
-              // constant.
+            if (canFoldAddIntoGEP(U, Op)) {
+              // A compatible add with a constant operand. Fold the constant.
               ConstantInt *CI =
               cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
               TmpOffset += CI->getSExtValue() * S;
diff --git a/lib/Target/PowerPC/PPCFastISel.cpp b/lib/Target/PowerPC/PPCFastISel.cpp
index 4f8e6c1..09117e7 100644
--- a/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/lib/Target/PowerPC/PPCFastISel.cpp
@@ -336,13 +336,8 @@ bool PPCFastISel::PPCComputeAddress(const Value *Obj, Address &Addr) {
               TmpOffset += CI->getSExtValue() * S;
               break;
             }
-            if (isa<AddOperator>(Op) &&
-                (!isa<Instruction>(Op) ||
-                 FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-                 == FuncInfo.MBB) &&
-                isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-              // An add (in the same block) with a constant operand. Fold the
-              // constant.
+            if (canFoldAddIntoGEP(U, Op)) {
+              // A compatible add with a constant operand. Fold the constant.
               ConstantInt *CI =
               cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
               TmpOffset += CI->getSExtValue() * S;
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 928dea9..97f96ab 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -561,13 +561,8 @@ redo_gep:
           Disp += CI->getSExtValue() * S;
           break;
         }
-        if (isa<AddOperator>(Op) &&
-            (!isa<Instruction>(Op) ||
-             FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-               == FuncInfo.MBB) &&
-            isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-          // An add (in the same block) with a constant operand. Fold the
-          // constant.
+        if (canFoldAddIntoGEP(U, Op)) {
+          // A compatible add with a constant operand. Fold the constant.
           ConstantInt *CI =
             cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
           Disp += CI->getSExtValue() * S;
-- 
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