Fixes regression in progs/demos/convolution.c due to loop unrolling.
This also allows the following to be compiled correctly:
for (int i = 0; i < n; i++) {
int i;
...
}
This fix is a bit of a hack, however. The better fix would be to change
the slang_shader.syn grammar. Will revisit that...
1-component structs such as "struct foo { float x; }" could get placed at
any position within a register. This caused some trouble computing the
field offset which assumed all struct objects were placed at R.x.
It would be unusual to hit this case in normal shaders.
(cherry picked from master, commit ca03e881a8)
1-component structs such as "struct foo { float x; }" could get placed at
any position within a register. This caused some trouble computing the
field offset which assumed all struct objects were placed at R.x.
It would be unusual to hit this case in normal shaders.
These functions need to return the final computed value.
Now expressions such as a = (b += c) work properly.
Also, no need to use __asm intrinsics in these functions. The resulting
code is the same when using ordinary arithmetic operators and is more legible.
There was a note in state.c about _Active deserving to die, and there were
potential issues with it due to i965 forgetting to set _UseTexEnvProgram.
Removing both simplifies things.
Reviewed-by: Brian Paul <brianp@vmware.com>
Add a "max complexity" heuristic to allow unrolling long loops with small
bodies and short loops with large bodies.
The loop unroll limits may need further tweaking...
Loops such as this will be unrolled:
for (i = 0; i < 4; ++i) {
body;
}
where 'body' isn't too large.
This also helps to fix the issue reported in bug #19190. The problem there
is indexing vector types with a variable index. For example:
vec4 v;
v[2] = 1.0; // equivalent to v.z = 1.0
v[i] = 2.0; // variable index into vector!!
Since the for-i loop can be unrolled, we can avoid the problems associated
with variable indexing into a vector (at least in this case).
