Author: johannes
Date: Tue Jan 8 18:16:55 2008
New Revision: 45765
URL: http://llvm.org/viewvc/llvm-project?rev=45765&view=rev
Log:
Watch out for overflow rounding up sizes of large objects.
Modified:
llvm-gcc-4.2/trunk/gcc/llvm-types.cpp
Modified: llvm-gcc-4.2/trunk/gcc/llvm-types.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-types.cpp?rev=45765&r1=45764&r2=45765&view=diff
==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-types.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-types.cpp Tue Jan 8 18:16:55 2008
@@ -1706,14 +1706,25 @@
// compensated as far as LLVM's translation code is concerned; now we
// have fixed that, and have to fix the size also.
if (TYPE_SIZE (type) && TREE_CODE(TYPE_SIZE(type)) == INTEGER_CST) {
- TYPE_SIZE(type) = build_int_cst(
- TREE_TYPE(TYPE_SIZE(type)),
- (TREE_INT_CST_LOW(TYPE_SIZE(type))+TYPE_ALIGN(type)-1) &
- ~(TYPE_ALIGN(type)-1));
- TYPE_SIZE_UNIT(type) = build_int_cst(
- TREE_TYPE(TYPE_SIZE_UNIT(type)),
- (TREE_INT_CST_LOW(TYPE_SIZE_UNIT(type))+TYPE_ALIGN_UNIT(type)-1) &
- ~(TYPE_ALIGN_UNIT(type)-1));
+ // This computes (size+align-1) & ~(align-1)
+ // NB "sizetype" is #define'd in one of the gcc headers. Gotcha!
+ tree size_type = TREE_TYPE(TYPE_SIZE(type));
+ tree alignm1 = fold_build2(PLUS_EXPR, size_type,
+ build_int_cst(size_type, TYPE_ALIGN(type)),
+ fold_build1(NEGATE_EXPR, size_type,
+ build_int_cst(size_type, 1)));
+ tree lhs = fold_build2(PLUS_EXPR, size_type, TYPE_SIZE(type), alignm1);
+ tree rhs = fold_build1(BIT_NOT_EXPR, size_type, alignm1);
+ TYPE_SIZE(type) = fold_build2(BIT_AND_EXPR, size_type, lhs, rhs);
+
+ size_type = TREE_TYPE(TYPE_SIZE_UNIT(type));
+ alignm1 = fold_build2(PLUS_EXPR, size_type,
+ build_int_cst(size_type,
TYPE_ALIGN_UNIT(type)),
+ fold_build1(NEGATE_EXPR, size_type,
+ build_int_cst(size_type, 1)));
+ lhs = fold_build2(PLUS_EXPR, size_type, TYPE_SIZE_UNIT(type), alignm1);
+ rhs = fold_build1(BIT_NOT_EXPR, size_type, alignm1);
+ TYPE_SIZE_UNIT(type) = fold_build2(BIT_AND_EXPR, size_type, lhs, rhs);
}
}
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
