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Fix number to real mask generation 

The << operator may not be defined when the RHS is greater than or
equal to the LHS width. To work around the problem the mask is
incrementally generated.
This commit is contained in:
Cary R 2007-10-19 11:21:19 -07:00 committed by Stephen Williams
parent 3543c0605c
commit 54aae2c1c2
1 changed files with 3 additions and 2 deletions
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5
tgt-vvp/eval_real.c
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@ -111,10 +111,11 @@ static int draw_number_real(ivl_expr_t exp)
int res = allocate_word(); int res = allocate_word();
const char*bits = ivl_expr_bits(exp); const char*bits = ivl_expr_bits(exp);
unsigned wid = ivl_expr_width(exp); unsigned wid = ivl_expr_width(exp);
unsigned long mant = 0; unsigned long mant = 0, mask = -1UL;
int vexp = 0x1000; int vexp = 0x1000;
for (idx = 0 ; idx < wid ; idx += 1) { for (idx = 0 ; idx < wid ; idx += 1) {
mask <<= 1;
if (bits[idx] == '1') if (bits[idx] == '1')
mant |= 1 << idx; mant |= 1 << idx;
} }
@ -129,7 +130,7 @@ static int draw_number_real(ivl_expr_t exp)
mant variable. This would lead to spurious '1' bits in the mant variable. This would lead to spurious '1' bits in the
high bits of mant that are masked by ~((-1UL)<<wid). */ high bits of mant that are masked by ~((-1UL)<<wid). */
if (ivl_expr_signed(exp) && (bits[wid-1] == '1')) { if (ivl_expr_signed(exp) && (bits[wid-1] == '1')) {
mant = (0-mant) & ~((-1UL) << wid); mant = (0-mant) & ~(mask);
vexp |= 0x4000; vexp |= 0x4000;
} }