luke
/
iverilog
mirror of https://github.com/steveicarus/iverilog.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Optimize draw_number_vec4 to use %pushi/vec4 zero-padding.

This commit is contained in:
Stephen Williams 2014-11-14 18:37:10 -08:00
parent 0601b4e43b
commit c2ca9c3b73
1 changed files with 16 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
tgt-vvp/eval_vec4.c
View File

@ -644,6 +644,13 @@ static void draw_concat_vec4(ivl_expr_t expr)
} }
} }
/*
* Push a number into the vec4 stack using %pushi/vec4
* instructions. The %pushi/vec4 instruction can only handle up to 32
* non-zero bits, so if there are more than that, then generate
* multiple %pushi/vec4 statements, and use %concat/vec4 statements to
* concatenate the vectors into the desired result.
*/
static void draw_number_vec4(ivl_expr_t expr) static void draw_number_vec4(ivl_expr_t expr)
{ {
unsigned long val0 = 0; unsigned long val0 = 0;
@ -678,8 +685,15 @@ static void draw_number_vec4(ivl_expr_t expr)
break; break;
} }
accum += 1; accum += 1;
if (accum == 32) {
fprintf(vvp_out, " %%pushi/vec4 %lu, %lu, 32;\n", val0, valx); /* Collect as many bits as can be written by a single
%pushi/vec4 instruction. This may be more than 32 if
the higher bits are zero, but if the currently
accumulated value fills what a %pushi/vec4 can do,
then write it out, generate a %concat/vec4, and set
up to handle more bits. */
if ( (val0|valx) & 0x80000000UL ) {
fprintf(vvp_out, " %%pushi/vec4 %lu, %lu, %d;\n", val0, valx, accum);
accum = 0; accum = 0;
val0 = 0; val0 = 0;
valx = 0; valx = 0;