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Was a little too aggressive with the lossless elab_and_eval 

The index expressions ARE self-sized context, we just need to
force the EXPAND flag to make this work.
This commit is contained in:
Stephen Williams 2014-01-17 18:22:11 -08:00
parent dfaed128c0
commit 078a3fd409
2 changed files with 13 additions and 16 deletions
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27
netmisc.cc
View File

@ -476,13 +476,6 @@ void indices_to_expressions(Design*des, NetScope*scope,
{ {
ivl_assert(*loc, count <= src.size()); ivl_assert(*loc, count <= src.size());
int need_wid = ceil(log2(need_addr)) + 1;
if (debug_elaborate) {
cerr << loc->get_fileline() << ": indices_to_expressions: "
<< "To address " << need_addr << " words, "
<< "we need " << need_wid << " bits." << endl;
}
flags.invalid = false; flags.invalid = false;
flags.variable = false; flags.variable = false;
flags.undefined = false; flags.undefined = false;
@ -497,7 +490,7 @@ void indices_to_expressions(Design*des, NetScope*scope,
} }
ivl_assert(*loc, cur->msb); ivl_assert(*loc, cur->msb);
NetExpr*word_index = elab_and_eval_min_width(des, scope, cur->msb, need_wid, need_const); NetExpr*word_index = elab_and_eval_lossless(des, scope, cur->msb, -2, need_const);
if (word_index == 0) if (word_index == 0)
flags.invalid = true; flags.invalid = true;
@ -741,13 +734,13 @@ NetExpr* condition_reduce(NetExpr*expr)
static NetExpr* do_elab_and_eval(Design*des, NetScope*scope, PExpr*pe, static NetExpr* do_elab_and_eval(Design*des, NetScope*scope, PExpr*pe,
int context_width, bool need_const, bool annotatable, int context_width, bool need_const, bool annotatable,
bool width_is_min, bool force_expand,
ivl_variable_type_t cast_type) ivl_variable_type_t cast_type)
{ {
PExpr::width_mode_t mode = PExpr::SIZED; PExpr::width_mode_t mode = PExpr::SIZED;
if ((context_width == -2) && !gn_strict_expr_width_flag) if ((context_width == -2) && !gn_strict_expr_width_flag)
mode = PExpr::EXPAND; mode = PExpr::EXPAND;
if (width_is_min) if (force_expand)
mode = PExpr::EXPAND; mode = PExpr::EXPAND;
pe->test_width(des, scope, mode); pe->test_width(des, scope, mode);
@ -769,7 +762,7 @@ static NetExpr* do_elab_and_eval(Design*des, NetScope*scope, PExpr*pe,
<< "returns type=" << pe->expr_type() << "returns type=" << pe->expr_type()
<< ", context_width=" << context_width << ", context_width=" << context_width
<< ", signed=" << pe->has_sign() << ", signed=" << pe->has_sign()
<< ", width_is_min=" << width_is_min << ", force_expand=" << force_expand
<< ", expr_width=" << expr_width << ", expr_width=" << expr_width
<< ", mode=" << PExpr::width_mode_name(mode) << endl; << ", mode=" << PExpr::width_mode_name(mode) << endl;
cerr << pe->get_fileline() << ": : " cerr << pe->get_fileline() << ": : "
@ -778,7 +771,7 @@ static NetExpr* do_elab_and_eval(Design*des, NetScope*scope, PExpr*pe,
// If we can get the same result using a smaller expression // If we can get the same result using a smaller expression
// width, do so. // width, do so.
if ((context_width > 0) && (!width_is_min) if ((context_width > 0) && (!force_expand)
&& (pe->expr_type() != IVL_VT_REAL) && (pe->expr_type() != IVL_VT_REAL)
&& (expr_width > (unsigned)context_width)) { && (expr_width > (unsigned)context_width)) {
expr_width = max(pe->min_width(), (unsigned)context_width); expr_width = max(pe->min_width(), (unsigned)context_width);
@ -822,7 +815,7 @@ static NetExpr* do_elab_and_eval(Design*des, NetScope*scope, PExpr*pe,
// If the context_width sent is is actually the minimim width, // If the context_width sent is is actually the minimim width,
// then raise the context_width to be big enough for the // then raise the context_width to be big enough for the
// lossless expression. // lossless expression.
if (width_is_min && context_width > 0) { if (force_expand && context_width > 0) {
context_width = max(context_width, (int)expr_width); context_width = max(context_width, (int)expr_width);
} }
@ -844,11 +837,15 @@ NetExpr* elab_and_eval(Design*des, NetScope*scope, PExpr*pe,
need_const, annotatable, false, cast_type); need_const, annotatable, false, cast_type);
} }
NetExpr* elab_and_eval_min_width(Design*des, NetScope*scope, PExpr*pe, /*
* This variant of elab_and_eval does the expression losslessly, no
* matter what the generation of verilog. This is in support of
* certain special contexts, notably index expressions.
*/
NetExpr* elab_and_eval_lossless(Design*des, NetScope*scope, PExpr*pe,
int context_width, bool need_const, bool annotatable, int context_width, bool need_const, bool annotatable,
ivl_variable_type_t cast_type) ivl_variable_type_t cast_type)
{ {
ivl_assert(*pe, context_width > 0);
return do_elab_and_eval(des, scope, pe, context_width, return do_elab_and_eval(des, scope, pe, context_width,
need_const, annotatable, true, cast_type); need_const, annotatable, true, cast_type);
} }

2
netmisc.h
View File

@ -246,7 +246,7 @@ extern NetExpr* elab_and_eval(Design*des, NetScope*scope,
bool annotatable =false, bool annotatable =false,
ivl_variable_type_t cast_type =IVL_VT_NO_TYPE); ivl_variable_type_t cast_type =IVL_VT_NO_TYPE);
extern NetExpr* elab_and_eval_min_width(Design*des, NetScope*scope, extern NetExpr* elab_and_eval_lossless(Design*des, NetScope*scope,
PExpr*pe, int context_width, PExpr*pe, int context_width,
bool need_const =false, bool need_const =false,
bool annotatable =false, bool annotatable =false,