scc

Simple C99 Compiler
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commit 79ccb978a8d4f8c9c9700bb16d2b97625f3f1dd4
parent 101edd9a3b5d71aecd5ed30c70b2ad011e27a66d
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed, 26 Aug 2015 22:25:35 +0200

Simplify expression like *& or &*

This kind of expressions are common in array expressions
and the can simplify a lot the IR generated.

Diffstat:
cc1/expr.c | 27++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/cc1/expr.c b/cc1/expr.c @@ -358,6 +358,12 @@ decay(Node *np) switch (tp->op) { case ARY: tp = tp->type; + if (np->op == OPTR) { + Node *new = np->left; + free(np); + new->type = mktype(tp, PTR, 0, NULL); + return new; + } case FTN: break; default: @@ -539,14 +545,16 @@ parithmetic(char op, Node *lp, Node *rp) } if (BTYPE(rp) != INT) goto incorrect; + rp = convert(promote(rp), sizettype, 0); - rp = node(OMUL, sizettype, rp, size); - rp = node(OCAST, tp, rp, NULL); + rp = simplify(OMUL, sizettype, rp, size); + rp = convert(rp, tp, 1); - return node(OADD, tp, lp, rp); + return simplify(OADD, tp, lp, rp); incorrect: - error("incorrect arithmetic operands"); + errorp("incorrect arithmetic operands"); + return node(OADD, tp, lp, rp); } static Node * @@ -752,6 +760,11 @@ address(char op, Node *np) error("lvalue required in unary expression"); if (np->symbol && (np->sym->flags & ISREGISTER)) error("address of register variable '%s' requested", yytext); + if (np->op == OPTR) { + Node *new = np->left; + free(np); + return new; + } return node(op, mktype(np->type, PTR, 0, NULL), np, NULL); } @@ -761,8 +774,12 @@ content(char op, Node *np) switch (BTYPE(np)) { case ARY: case FTN: - np = decay(np); case PTR: + if (np->op == OADDR) { + Node *new = np->left; + free(np); + return new; + } np = node(op, np->type->type, np, NULL); np->lvalue = 1; return np;