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tccgen: use lvalue as result from bitfield assignment

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test case:

    #include <stdio.h>
    int main(int argc, char **argv)
    {
        struct _s { unsigned a:9, b:5, c:7; } _s, *s = &_s;
        int n = 250;
        s->a = s->b = s->c = n + 4;
        printf("--> %d / %d / %d\n", s->a, s->b, s->c);
        return 0;
    }

before:
--> 254 / 30 / 126
now:
--> 30 / 30 / 126
This commit is contained in:
grischka 2014-09-23 12:30:08 +02:00
parent 87d879aa7b
commit 9d7fb33360
1 changed files with 5 additions and 7 deletions
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12
tccgen.c
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@ -2520,16 +2520,15 @@ ST_FUNC void vstore(void)
/* leave source on stack */
} else if (ft & VT_BITFIELD) {
/* bitfield store handling */
/* save lvalue as expression result (example: s.b = s.a = n;) */
vdup(), vtop[-1] = vtop[-2];
bit_pos = (ft >> VT_STRUCT_SHIFT) & 0x3f;
bit_size = (ft >> (VT_STRUCT_SHIFT + 6)) & 0x3f;
/* remove bit field info to avoid loops */
vtop[-1].type.t = ft & ~(VT_BITFIELD | (-1 << VT_STRUCT_SHIFT));
/* duplicate source into other register */
gv_dup();
vswap();
vrott(3);
if((ft & VT_BTYPE) == VT_BOOL) {
gen_cast(&vtop[-1].type);
vtop[-1].type.t = (vtop[-1].type.t & ~VT_BTYPE) | (VT_BYTE | VT_UNSIGNED);
@ -2561,8 +2560,7 @@ ST_FUNC void vstore(void)
gen_op('|');
/* store result */
vstore();
/* pop off shifted source from "duplicate source..." above */
/* ... and discard */
vpop();
} else {