diff options
| -rw-r--r-- | src/cmd/5g/cgen.c | 106 |
1 files changed, 48 insertions, 58 deletions
diff --git a/src/cmd/5g/cgen.c b/src/cmd/5g/cgen.c index dfee75e0e..1362cc07d 100644 --- a/src/cmd/5g/cgen.c +++ b/src/cmd/5g/cgen.c @@ -76,46 +76,6 @@ cgen(Node *n, Node *res) goto ret; } - if(!res->addable) { - if(n->ullman > res->ullman) { - regalloc(&n1, n->type, res); - cgen(n, &n1); - if(n1.ullman > res->ullman) { - dump("n1", &n1); - dump("res", res); - fatal("loop in cgen"); - } - cgen(&n1, res); - regfree(&n1); - goto ret; - } - - if(res->ullman >= UINF) - goto gen; - - a = optoas(OAS, res->type); - if(sudoaddable(a, res, &addr, &w)) { - if(n->op != OREGISTER) { - regalloc(&n2, res->type, N); - cgen(n, &n2); - p1 = gins(a, &n2, N); - regfree(&n2); - } else - p1 = gins(a, n, N); - p1->to = addr; - if(debug['g']) - print("%P [ignore previous line]\n", p1); - sudoclean(); - goto ret; - } - - gen: - igen(res, &n1, N); - cgen(n, &n1); - regfree(&n1); - goto ret; - } - // update addressability for string, slice // can't do in walk because n->left->addable // changes if n->left is an escaping local variable. @@ -130,8 +90,9 @@ cgen(Node *n, Node *res) break; } - if(n->addable) { - if (n->op == OREGISTER || is64(n->type) || is64(res->type)) { + // if both are addressable, move + if(n->addable && res->addable) { + if (is64(n->type) || is64(res->type) || n->op == OREGISTER || res->op == OREGISTER) { gmove(n, res); } else { regalloc(&n1, n->type, N); @@ -142,6 +103,51 @@ cgen(Node *n, Node *res) goto ret; } + // if both are not addressable, use a temporary. + if(!n->addable && !res->addable) { + // could use regalloc here sometimes, + // but have to check for ullman >= UINF. + tempname(&n1, n->type); + cgen(n, &n1); + cgen(&n1, res); + return; + } + + // if result is not addressable directly but n is, + // compute its address and then store via the address. + if(!res->addable) { + igen(res, &n1, N); + cgen(n, &n1); + regfree(&n1); + return; + } + + // if n is sudoaddable generate addr and move + if (!is64(n->type) && !is64(res->type)) { + a = optoas(OAS, n->type); + if(sudoaddable(a, n, &addr, &w)) { + if (res->op != OREGISTER) { + regalloc(&n2, res->type, N); + p1 = gins(a, N, &n2); + p1->from = addr; + if(debug['g']) + print("%P [ignore previous line]\n", p1); + gmove(&n2, res); + regfree(&n2); + } else { + p1 = gins(a, N, res); + p1->from = addr; + if(debug['g']) + print("%P [ignore previous line]\n", p1); + } + sudoclean(); + goto ret; + } + } + + // otherwise, the result is addressable but n is not. + // let's do some computation. + nl = n->left; nr = n->right; @@ -172,22 +178,6 @@ cgen(Node *n, Node *res) cgen64(n, res); return; } - } else { - a = optoas(OAS, n->type); - if(sudoaddable(a, n, &addr, &w)) { - if(res->op == OREGISTER) { - p1 = gins(a, N, res); - p1->from = addr; - } else { - regalloc(&n2, n->type, N); - p1 = gins(a, N, &n2); - p1->from = addr; - gins(a, &n2, res); - regfree(&n2); - } - sudoclean(); - goto ret; - } } switch(n->op) { |