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Support negative bit indexes.

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Allow arbitrary characters in symbols (to make '-' work.)
Final merge from negative_lsb branch.
This commit is contained in:
Wilson Snyder
2008-10-06 09:59:22 -04:00
parent cdd6ea8e60
commit 3b1929259a
18 changed files with 230 additions and 114 deletions
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src/V3Width.cpp
+6 -4
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@@ -238,9 +238,9 @@ private:
if (!lsbConstp) nodep->v3error("LSB of bit range isn't a constant");
nodep->width(1,1); return;
}
uint32_t msb = msbConstp->asInt();
uint32_t lsb = lsbConstp->asInt();
if (msb > (1UL<<28)) nodep->v3error("MSB of bit range is huge; vector of over 1billion bits: 0x"<<hex<<msb);
int msb = msbConstp->toSInt();
int lsb = lsbConstp->toSInt();
if (msb > (1<<28)) nodep->v3error("MSB of bit range is huge; vector of over 1billion bits: 0x"<<hex<<msb);
if (msb<lsb) {
// If it's a array, ok to have either ordering, we'll just correct
// So, see if we're sitting under a variable's arrayp.
@@ -296,7 +296,7 @@ private:
int fromlsb = 0;
AstNodeVarRef* varrp = nodep->fromp()->castNodeVarRef();
if (varrp && varrp->varp()->rangep()) { // Selecting a bit from a multibit register
frommsb = varrp->varp()->msb();
frommsb = varrp->varp()->msbMaxSelect(); // Corrected for negative lsb
fromlsb = varrp->varp()->lsb();
}
int selwidth = V3Number::log2b(frommsb+1-1)+1; // Width to address a bit
@@ -332,6 +332,8 @@ private:
frommsb = varrp->varp()->arrayp(dimension)->msbConst();
fromlsb = varrp->varp()->arrayp(dimension)->lsbConst();
if (fromlsb>frommsb) {int t=frommsb; frommsb=fromlsb; fromlsb=t; }
// However, if the lsb<0 we may go negative, so need more bits!
if (fromlsb < 0) frommsb += -fromlsb;
nodep->width(outwidth,outwidth); // Width out = width of array
}
int selwidth = V3Number::log2b(frommsb+1-1)+1; // Width to address a bit