scc

simple C compiler
git clone git://git.2f30.org/scc
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commit 73173f33f7fe04ab610b0be20afef392eda59fed
parent 9312f29f82dc8833bffdfa6eef5577865056d20c
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Fri,  3 Feb 2017 11:03:28 +0100

[cc1] Move castcode() from fold.c to expr.c

This function was only used in expr.c and it is not related
to the code in fold.c.

Diffstat:
Mcc1/cc1.h | 1-
Mcc1/expr.c | 58++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/cc1/cc1.h b/cc1/cc1.h @@ -420,7 +420,6 @@ extern void freetree(Node *np); /* fold.c */ extern Node *simplify(int op, Type *tp, Node *lp, Node *rp); -extern Node *castcode(Node *np, Type *newtp); extern TUINT ones(int nbytes); /* expr.c */ diff --git a/cc1/expr.c b/cc1/expr.c @@ -240,6 +240,64 @@ numericaluop(int op, Node *np) if (op == OADD) return np; return simplify(op, np->type, np, NULL); + return node(op, np->type, np, NULL); +} + +/* TODO: check validity of types */ +static Node * +castcode(Node *np, Type *newtp) +{ + TUINT negmask, mask, u; + Type *oldtp = np->type; + Symbol aux, *sym, *osym = np->sym; + + if (!(np->flags & NCONST)) + goto noconstant; + + switch (newtp->op) { + case PTR: + case INT: + case ENUM: + switch (oldtp->op) { + case PTR: + case INT: + case ENUM: + u = (oldtp->prop & TSIGNED) ? osym->u.i : osym->u.u; + break; + case FLOAT: + oldtp = newtp; + u = osym->u.f; + break; + default: + goto noconstant; + } + mask = ones(newtp->size); + if (newtp->prop & TSIGNED) { + negmask = ~mask; + if (u & (negmask >> 1) & mask) + u |= negmask; + aux.u.i = u; + } else { + aux.u.u = u & mask; + } + break; + case FLOAT: + /* FIXME: The cast can be from another float type */ + aux.u.f = (oldtp->prop & TSIGNED) ? osym->u.i : osym->u.u; + break; + default: + goto noconstant; + } + + sym = newsym(NS_IDEN, NULL); + np->type = sym->type = newtp; + np->sym = sym; + sym->u = aux.u; + + return np; + +noconstant: + return node(OCAST, newtp, np, NULL); } Node *