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Added some code to reverse evaluation order of assignment operators when possible

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This commit is contained in:
ceriel 1990-02-28 12:18:36 +00:00
parent 2236ff6d6a
commit 63e64680bd
2 changed files with 48 additions and 10 deletions
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29
lang/cem/cemcom.ansi/eval.c
View file

@ -392,6 +392,7 @@ EVAL(expr, val, code, true_label, false_label)
arith tmp = 0;
int compl; /* Complexity of left operand */
int newcode = left->ex_type->tp_size > 0; /* CJ */
int right_done = 0;
#ifndef NOBITFIELD
if (left->ex_type->tp_fund == FIELD) {
eval_field(expr, gencode);
@ -400,16 +401,32 @@ EVAL(expr, val, code, true_label, false_label)
#endif NOBITFIELD
if (newcode && left->ex_class == Value) {
compl = 0; /* Value */
}
else if (left->ex_depth == 1 &&
!(left->ex_flags & EX_SIDEEFFECTS)) {
compl = 1;
}
else compl = 2;
/* evaluate right-hand side first when possible,
but not for POSTINCR or PLUSPLUS, because then
we might miss a chance for increment instructions.
*/
if (compl != 2 &&
tp->tp_fund != POINTER &&
(oper == PLUSAB || oper == TIMESAB ||
oper == ANDAB || oper == XORAB || oper == ORAB)) {
right_done = 1;
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
}
if (compl == 0) {
load_val(left, RVAL);
}
else
if (left->ex_depth == 1 &&
!(left->ex_flags & EX_SIDEEFFECTS)) {
compl = 1;
if (compl == 1) {
EVAL(left, RVAL, newcode, NO_LABEL, NO_LABEL);
}
else {
compl = 2; /* otherwise */
EVAL(left, LVAL, newcode, NO_LABEL, NO_LABEL);
if (newcode) {
tmp = LocalPtrVar();
@ -424,7 +441,9 @@ EVAL(expr, val, code, true_label, false_label)
C_dup(ATW(left->ex_type->tp_size));
conversion(left->ex_type, tp);
}
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
if (! right_done) {
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
}
if (newcode) {
int dupval = gencode && oper != POSTINCR &&
oper != POSTDECR;

29
lang/cem/cemcom/eval.c
View file

@ -383,6 +383,7 @@ EVAL(expr, val, code, true_label, false_label)
arith tmp;
int compl; /* Complexity of left operand */
int newcode = left->ex_type->tp_size > 0; /* CJ */
int right_done = 0;
#ifndef NOBITFIELD
if (left->ex_type->tp_fund == FIELD) {
eval_field(expr, gencode);
@ -391,16 +392,32 @@ EVAL(expr, val, code, true_label, false_label)
#endif NOBITFIELD
if (newcode && left->ex_class == Value) {
compl = 0; /* Value */
}
else if (left->ex_depth == 1 &&
!(left->ex_flags & EX_SIDEEFFECTS)) {
compl = 1;
}
else compl = 2;
/* evaluate right-hand side first when possible,
but not for POSTINCR or PLUSPLUS, because then
we might miss a chance for increment instructions.
*/
if (compl != 2 &&
tp->tp_fund != POINTER &&
(oper == PLUSAB || oper == TIMESAB ||
oper == ANDAB || oper == XORAB || oper == ORAB)) {
right_done = 1;
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
}
if (compl == 0) {
load_val(left, RVAL);
}
else
if (left->ex_depth == 1 &&
!(left->ex_flags & EX_SIDEEFFECTS)) {
compl = 1;
if (compl == 1) {
EVAL(left, RVAL, newcode, NO_LABEL, NO_LABEL);
}
else {
compl = 2; /* otherwise */
EVAL(left, LVAL, newcode, NO_LABEL, NO_LABEL);
if (newcode) {
tmp = LocalPtrVar();
@ -415,7 +432,9 @@ EVAL(expr, val, code, true_label, false_label)
C_dup(ATW(left->ex_type->tp_size));
conversion(left->ex_type, tp);
}
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
if (! right_done) {
EVAL(right, RVAL, newcode, NO_LABEL, NO_LABEL);
}
if (newcode) {
int dupval = gencode && oper != POSTINCR &&
oper != POSTDECR;