diff options
Diffstat (limited to 'gcc/tree.def')
| -rw-r--r-- | gcc/tree.def | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/gcc/tree.def b/gcc/tree.def index a92d86f..a6247a7 100644 --- a/gcc/tree.def +++ b/gcc/tree.def @@ -257,13 +257,24 @@ DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0) /* First, the constants. */ -/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, - 32 bits each, giving us a 64 bit constant capability. INTEGER_CST - nodes can be shared, and therefore should be considered read only. - They should be copied, before setting a flag such as TREE_OVERFLOW. - If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique. - INTEGER_CST nodes are created for the integral types, for pointer - types and for vector and float types in some circumstances. */ +/* Contents are in an array of HOST_WIDE_INTs. + + We often access these constants both in their native precision and + in wider precisions (with the constant being implicitly extended + according to TYPE_SIGN). In each case, the useful part of the array + may be as wide as the precision requires but may be shorter when all + of the upper bits are sign bits. The length of the array when accessed + in the constant's native precision is given by TREE_INT_CST_NUNITS. + The length of the array when accessed in wider precisions is given + by TREE_INT_CST_EXT_NUNITS. Each element can be obtained using + TREE_INT_CST_ELT. + + INTEGER_CST nodes can be shared, and therefore should be considered + read only. They should be copied before setting a flag such as + TREE_OVERFLOW. If an INTEGER_CST has TREE_OVERFLOW already set, + it is known to be unique. INTEGER_CST nodes are created for the + integral types, for pointer types and for vector and float types in + some circumstances. */ DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0) /* Contents are in TREE_REAL_CST field. */ |