From 21ef70ed4f655151a983788ce634787c995c7e2f Mon Sep 17 00:00:00 2001
From: Nadav Rotem <nadav.rotem@intel.com>
Date: Tue, 28 Feb 2012 11:54:05 +0000
Subject: [PATCH] Fix a bug in the code that builds SDNodes from vector GEPs.

When the GEP index is a vector of pointers, the code that calculated the size
of the element started from the vector type, and not the contained pointer type.
As a result, instead of looking at the data element pointed by the vector, this
code used the size of the vector. This works for 32bit members (on 32bit
systems), but not for other types. Added code to peel the vector type and
added a test.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151626 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../SelectionDAG/SelectionDAGBuilder.cpp      |  4 ++
 test/CodeGen/X86/vector-gep.ll                | 45 ++++++++++++-------
 2 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index ca64c903f39..5eba2c3ea7c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3078,6 +3078,10 @@ void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {
 void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
   SDValue N = getValue(I.getOperand(0));
   Type *Ty = I.getOperand(0)->getType();
+  // If this is a vector of pointers, use the size of the
+  // vector element and not the size of the pointer.
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    Ty = VTy->getElementType();
 
   for (GetElementPtrInst::const_op_iterator OI = I.op_begin()+1, E = I.op_end();
        OI != E; ++OI) {
diff --git a/test/CodeGen/X86/vector-gep.ll b/test/CodeGen/X86/vector-gep.ll
index d032eda88be..3476e36c646 100644
--- a/test/CodeGen/X86/vector-gep.ll
+++ b/test/CodeGen/X86/vector-gep.ll
@@ -1,27 +1,27 @@
 ; RUN: llc < %s -march=x86 -mcpu=corei7-avx | FileCheck %s
 ; RUN: opt -instsimplify %s -disable-output
 
-;CHECK: AGEP0
+;CHECK: AGEP0:
 define <4 x i32*> @AGEP0(i32* %ptr) nounwind {
 entry:
   %vecinit.i = insertelement <4 x i32*> undef, i32* %ptr, i32 0
   %vecinit2.i = insertelement <4 x i32*> %vecinit.i, i32* %ptr, i32 1
   %vecinit4.i = insertelement <4 x i32*> %vecinit2.i, i32* %ptr, i32 2
   %vecinit6.i = insertelement <4 x i32*> %vecinit4.i, i32* %ptr, i32 3
-;CHECK: pslld
+;CHECK: pslld $2
 ;CHECK: padd
   %A2 = getelementptr <4 x i32*> %vecinit6.i, <4 x i32> <i32 1, i32 2, i32 3, i32 4>
-;CHECK: pslld
+;CHECK: pslld $2
 ;CHECK: padd
   %A3 = getelementptr <4 x i32*> %A2, <4 x i32> <i32 10, i32 14, i32 19, i32 233>
   ret <4 x i32*> %A3
 ;CHECK: ret
 }
 
-;CHECK: AGEP1
+;CHECK: AGEP1:
 define i32 @AGEP1(<4 x i32*> %param) nounwind {
 entry:
-;CHECK: pslld
+;CHECK: pslld $2
 ;CHECK: padd
   %A2 = getelementptr <4 x i32*> %param, <4 x i32> <i32 1, i32 2, i32 3, i32 4>
   %k = extractelement <4 x i32*> %A2, i32 3
@@ -30,10 +30,10 @@ entry:
 ;CHECK: ret
 }
 
-;CHECK: AGEP2
+;CHECK: AGEP2:
 define i32 @AGEP2(<4 x i32*> %param, <4 x i32> %off) nounwind {
 entry:
-;CHECK: pslld
+;CHECK: pslld $2
 ;CHECK: padd
   %A2 = getelementptr <4 x i32*> %param, <4 x i32> %off
   %k = extractelement <4 x i32*> %A2, i32 3
@@ -42,10 +42,10 @@ entry:
 ;CHECK: ret
 }
 
-;CHECK: AGEP3
+;CHECK: AGEP3:
 define <4 x i32*> @AGEP3(<4 x i32*> %param, <4 x i32> %off) nounwind {
 entry:
-;CHECK: pslld
+;CHECK: pslld $2
 ;CHECK: padd
   %A2 = getelementptr <4 x i32*> %param, <4 x i32> %off
   %v = alloca i32
@@ -54,24 +54,35 @@ entry:
 ;CHECK: ret
 }
 
-;CHECK: AGEP4
-define <4 x i8*> @AGEP4(<4 x i8*> %param, <4 x i32> %off) nounwind {
+;CHECK: AGEP4:
+define <4 x i16*> @AGEP4(<4 x i16*> %param, <4 x i32> %off) nounwind {
 entry:
-;CHECK: pslld
+; Multiply offset by two (add it to itself).
 ;CHECK: padd
-  %A = getelementptr <4 x i8*> %param, <4 x i32> %off
-  ret <4 x i8*> %A
+; add the base to the offset
+;CHECK: padd
+  %A = getelementptr <4 x i16*> %param, <4 x i32> %off
+  ret <4 x i16*> %A
 ;CHECK: ret
 }
 
-;CHECK: AGEP5
+;CHECK: AGEP5:
 define <4 x i8*> @AGEP5(<4 x i8*> %param, <4 x i8> %off) nounwind {
 entry:
-;CHECK: pslld
-;CHECK: padd
+;CHECK: paddd
   %A = getelementptr <4 x i8*> %param, <4 x i8> %off
   ret <4 x i8*> %A
 ;CHECK: ret
 }
 
 
+; The size of each element is 1 byte. No need to multiply by element size.
+;CHECK: AGEP6:
+define <4 x i8*> @AGEP6(<4 x i8*> %param, <4 x i32> %off) nounwind {
+entry:
+;CHECK-NOT: pslld
+  %A = getelementptr <4 x i8*> %param, <4 x i32> %off
+  ret <4 x i8*> %A
+;CHECK: ret
+}
+
-- 
2.34.1