The old code assumed that loop terminators will always be at
the start of the loop, resulting in otherwise unrollable
loops not being unrolled at all. For example the current
code would unroll:
int j = 0;
do {
if (j > 5)
break;
... do stuff ...
j++;
} while (j < 4);
But would fail to unroll the following as no iteration limit was
calculated because it failed to find the terminator:
int j = 0;
do {
... do stuff ...
j++;
} while (j < 4);
Also we would fail to unroll the following as we ended up
calculating the iteration limit as 6 rather than 4. The unroll
code then assumed we had 3 terminators rather the 2 as it
wasn't able to determine that "if (j > 5)" was redundant.
int j = 0;
do {
if (j > 5)
break;
... do stuff ...
if (bool(i))
break;
j++;
} while (j < 4);
This patch changes this pass to be more like the NIR unrolling pass.
With this change we handle loop terminators correctly and also
handle cases where the terminators have instructions in their
branches other than a break.
V2:
- fixed regression where loops with a break in else were never
unrolled in v1.
- fixed confusing/wrong naming of bools in complex unrolling.
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
These instructions will be executed on every iteration of the loop
we cannot drop them.
V2:
- move removal of unreachable terminators from the terminator list
to the same place they are removed from the IR as suggested by
Nicolai.
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Having this separate just makes the code harder to follow, and
requires an extra walk of the IR.
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Through the glsl headers we had an odd mix of guards be that
"ifndef", "pragma once" neither or both.
Simplify things by using the more common ones (ifndef) and annotating
all the sources, barring the generated builting header -
builtin_int64.h.
The final header - udivmod64.h - is [seemingly] unused and on its way
out (patch purge it is on the mailing list).
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Vedran Miletić <vedran@miletic.net>
Acked-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
