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Fix muldiv_c peepopt

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This commit is contained in:
Akash Levy 2024-10-21 02:09:56 -07:00
parent 3d127dff4a
commit 70eabb12e8
1 changed files with 12 additions and 8 deletions
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20
passes/pmgen/peepopt_muldiv_c.pmg
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@ -12,8 +12,6 @@ match mul
endmatch
code a b_const mul_y
printf("CODING MUL!!!\n");
// Get multiplier signals
a = port(mul, \A);
b_const = port(mul, \B);
@ -32,33 +30,39 @@ endcode
match div
// Select div of form (a * b_const) / c_const
select div->type == $div
index <SigSpec> port(div, \A) === port(mul, \Y)
// Check that b_const and c_const is constant
filter port(mul, \B).is_fully_const()
filter b_const.is_fully_const()
filter port(div, \B).is_fully_const()
endmatch
code
printf("CODING DIV!!!\n");
// Get div signals
SigSpec div_a = port(div, \A);
SigSpec c_const = port(div, \B);
SigSpec div_y = port(div, \Y);
// Get offset of multiplier result chunk in divider
int offset = GetSize(div_a) - GetSize(mul_y);
// Get properties and values of b_const and c_const
int b_const_width = mul->getParam(ID::B_WIDTH).as_int();
bool b_const_signed = mul->getParam(ID::B_SIGNED).as_bool();
bool c_const_signed = div->getParam(ID::B_SIGNED).as_bool();
int b_const_int = b_const.as_int(b_const_signed);
int c_const_int = c_const.as_int(c_const_signed);
int b_const_int_shifted = b_const_int << offset;
// Check that there are only zeros before offset
if (offset < 0 || !div_a.extract(0, offset).is_fully_zero())
reject;
// Check that b is divisible by c
if (b_const_int % c_const_int != 0)
if (b_const_int_shifted % c_const_int != 0)
reject;
// Rewire to only keep multiplier
mul->setPort(\B, Const(b_const_int / c_const_int, b_const_width));
mul->setPort(\B, Const(b_const_int_shifted / c_const_int, b_const_width));
mul->setPort(\Y, div_y);
// Remove divider