Francisco Casas : vkd3d-shader/tpf: Don't pass 0x4 as mask for vec4 constant src registers.

[Alexandre Julliard]

Module: vkd3d
Branch: master
Commit: 98b5eb474a0e583e7381cd8638d435fe7d77ebd0
URL:    https://gitlab.winehq.org/wine/vkd3d/-/commit/98b5eb474a0e583e7381cd8638d435...

Author: Francisco Casas <fcasas(a)codeweavers.com>
Date:   Wed Nov  1 20:50:33 2023 -0300

vkd3d-shader/tpf: Don't pass 0x4 as mask for vec4 constant src registers.

Co-authored-by: Evan Tang <etang(a)codeweavers.com>

Evan Tang reported that new fixmes appeared on the shader_runner when
running some of his tests after
f50d0ae2cbc5ee2a26fedd7b8aac2def62decd6c.

    vkd3d:652593:fixme:shader_sm4_read_src_param Unhandled mask 0x4.

The change to blame seems to be this added line in
sm4_src_from_constant_value().

    +    src->swizzle = VKD3D_SHADER_NO_SWIZZLE;

On tpf binaries the last 12 bits of each src register in an instruction
specify the swizzle, and there are 5 possible combinations:

    Dimension NONE
    -------- 00

    Dimension SCALAR
    -------- 01

    Dimension VEC4, with a 4 bit writemask:
    ---- xxxx 00 01

    Dimension VEC4, with an 8 bit swizzle:
    xx xx xx xx 01 01

    Dimension VEC4, with a 2bit scalar dimension number:
    ------ xx 10 01

So far, we have only seen src registers use 4 bit writemasks in a
single case: for vec4 constants, and it is always zero.

So we expect this:

    ---- 0000 00 01

Now, I probably wanted to initialize src->swizzle to zero when writing
constants, but VKD3D_SHADER_NO_SWIZZLE is not zero, it is actually the
default swizzle:

    11 10 01 00

And the last 4 bits (0x4) get written in the mask part, which causes
the reader to complain.

---

 libs/vkd3d-shader/tpf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/vkd3d-shader/tpf.c b/libs/vkd3d-shader/tpf.c
index afdf8473..8ae1657d 100644
--- a/libs/vkd3d-shader/tpf.c
+++ b/libs/vkd3d-shader/tpf.c
@@ -3790,7 +3790,7 @@ static void sm4_dst_from_node(struct vkd3d_shader_dst_param *dst, const struct h
 static void sm4_src_from_constant_value(struct vkd3d_shader_src_param *src,
         const struct hlsl_constant_value *value, unsigned int width, unsigned int map_writemask)
 {
-    src->swizzle = VKD3D_SHADER_NO_SWIZZLE;
+    src->swizzle = 0;
     src->reg.type = VKD3DSPR_IMMCONST;
     if (width == 1)
     {