summaryrefslogtreecommitdiff
path: root/lib/Analysis/BasicAliasAnalysis.cpp
diff options
context:
space:
mode:
authorEli Friedman <eli.friedman@gmail.com>2011-09-08 02:37:07 +0000
committerEli Friedman <eli.friedman@gmail.com>2011-09-08 02:37:07 +0000
commit184166da619ac7f14d8460b4b0f8f85bfc601ebc (patch)
tree1462d75b531efb2bd36edb121f372363b2092d62 /lib/Analysis/BasicAliasAnalysis.cpp
parent81ac8ddc674d1589dbba97f752ec77750901f510 (diff)
downloadllvm-184166da619ac7f14d8460b4b0f8f85bfc601ebc.tar.gz
llvm-184166da619ac7f14d8460b4b0f8f85bfc601ebc.tar.bz2
llvm-184166da619ac7f14d8460b4b0f8f85bfc601ebc.tar.xz
A couple minor corrections to r139276.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139277 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/BasicAliasAnalysis.cpp')
-rw-r--r--lib/Analysis/BasicAliasAnalysis.cpp28
1 files changed, 14 insertions, 14 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 45bc624d83..4b7d2f5d9d 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -977,20 +977,20 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
// Try to distinguish something like &A[i][1] against &A[42][0].
// Grab the least significant bit set in any of the scales.
- uint64_t Modulo = 0;
- for (unsigned i = 0, e = GEP1VariableIndices.size();
- i != e; ++i)
- Modulo |= (uint64_t)GEP1VariableIndices[0].Scale;
- Modulo = Modulo ^ (Modulo & (Modulo - 1));
-
- // We can compute the difference between the two addresses
- // mod Modulo. Check whether that difference guarantees that the
- // two locations do not alias.
- uint64_t ModOffset = (uint64_t)GEP1BaseOffset & (Modulo - 1);
- if (V1Size != UnknownSize && V2Size != UnknownSize &&
- ModOffset >= V2Size && V1Size <= Modulo - ModOffset)
- return NoAlias;
-
+ if (!GEP1VariableIndices.empty()) {
+ uint64_t Modulo = 0;
+ for (unsigned i = 0, e = GEP1VariableIndices.size(); i != e; ++i)
+ Modulo |= (uint64_t)GEP1VariableIndices[i].Scale;
+ Modulo = Modulo ^ (Modulo & (Modulo - 1));
+
+ // We can compute the difference between the two addresses
+ // mod Modulo. Check whether that difference guarantees that the
+ // two locations do not alias.
+ uint64_t ModOffset = (uint64_t)GEP1BaseOffset & (Modulo - 1);
+ if (V1Size != UnknownSize && V2Size != UnknownSize &&
+ ModOffset >= V2Size && V1Size <= Modulo - ModOffset)
+ return NoAlias;
+ }
// Statically, we can see that the base objects are the same, but the
// pointers have dynamic offsets which we can't resolve. And none of our