[llvm] r275866 - CodeGenPrep: use correct function to determine Global's alignment.

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Mon Jul 18 13:28:52 2016
New Revision: 275866

URL: http://llvm.org/viewvc/llvm-project?rev=275866&view=rev
Log:
CodeGenPrep: use correct function to determine Global's alignment.

Elsewhere (particularly computeKnownBits) we assume that a global will be
aligned to the value returned by Value::getPointerAlignment. This is used to
boost the alignment on memcpy/memset, so any target-specific request can only
increase that value.

Modified:
    llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
    llvm/trunk/test/CodeGen/ARM/memfunc.ll

Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=275866&r1=275865&r2=275866&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Mon Jul 18 13:28:52 2016
@@ -1780,7 +1780,7 @@ bool CodeGenPrepare::optimizeCallInst(Ca
       // forbidden.
       GlobalVariable *GV;
       if ((GV = dyn_cast<GlobalVariable>(Val)) && GV->canIncreaseAlignment() &&
-          GV->getAlignment() < PrefAlign &&
+          GV->getPointerAlignment(*DL) < PrefAlign &&
           DL->getTypeAllocSize(GV->getValueType()) >=
               MinSize + Offset2)
         GV->setAlignment(PrefAlign);

Modified: llvm/trunk/test/CodeGen/ARM/memfunc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/memfunc.ll?rev=275866&r1=275865&r2=275866&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/memfunc.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/memfunc.ll Mon Jul 18 13:28:52 2016
@@ -386,6 +386,8 @@ entry:
 @arr5 = weak global [7 x i8] c"\01\02\03\04\05\06\07", align 1
 @arr6 = weak_odr global [7 x i8] c"\01\02\03\04\05\06\07", align 1
 @arr7 = external global [7 x i8], align 1
+ at arr8 = internal global [128 x i8] undef
+ at arr9 = weak_odr global [128 x i8] undef
 define void @f9(i8* %dest, i32 %n) {
 entry:
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr1, i32 0, i32 0), i32 %n, i32 1, i1 false)
@@ -395,6 +397,8 @@ entry:
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr5, i32 0, i32 0), i32 %n, i32 1, i1 false)
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr6, i32 0, i32 0), i32 %n, i32 1, i1 false)
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @arr7, i32 0, i32 0), i32 %n, i32 1, i1 false)
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([128 x i8], [128 x i8]* @arr8, i32 0, i32 0), i32 %n, i32 1, i1 false)
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* getelementptr inbounds ([128 x i8], [128 x i8]* @arr9, i32 0, i32 0), i32 %n, i32 1, i1 false)
 
   unreachable
 }
@@ -417,6 +421,11 @@ entry:
 ; CHECK: arr5:
 ; CHECK-NOT: .p2align
 ; CHECK: arr6:
+; CHECK: .p2align 4
+; CHECK: arr8:
+; CHECK: .p2align 4
+; CHECK: arr9:
+
 ; CHECK-NOT: arr7:
 
 declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind