diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 88005429c9c3..5cb05f8aaaba 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Sun Oct 26 13:31:47 1997 Jim Wilson (wilson@cygnus.com) + + * expr.c (expand_expr, case INDIRECT_REF): Optimize a reference + to an element in a constant string. + Sun Oct 26 11:41:49 1997 Jason Merrill * dwarf2out.c (output_call_frame_info): The CIE pointer is now a 32 diff --git a/gcc/expr.c b/gcc/expr.c index 920ffbc24616..5cd1b435780e 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -5406,6 +5406,18 @@ expand_expr (exp, target, tmode, modifier) { tree exp1 = TREE_OPERAND (exp, 0); tree exp2; + tree index; + tree string = string_constant (exp1, &index); + int i; + + if (string + && TREE_CODE (string) == STRING_CST + && TREE_CODE (index) == INTEGER_CST + && !TREE_INT_CST_HIGH (index) + && (i = TREE_INT_CST_LOW (index)) < TREE_STRING_LENGTH (string) + && GET_MODE_CLASS (mode) == MODE_INT + && GET_MODE_SIZE (mode) == 1) + return GEN_INT (TREE_STRING_POINTER (string)[i]); op0 = expand_expr (exp1, NULL_RTX, VOIDmode, EXPAND_SUM); op0 = memory_address (mode, op0);