Generated frag shader may assign alpha channel of dot product statement

[HadetTheUndying]

https://xemu.app/titles/4d530046/#Phantom-Dust

Title "Phantom Dust" will crash when entering campaign.

Failing Fragment Shader from "Phantom Dust"

#version 330

struct VertexData {
  float inv_w;
  vec4 D0;
  vec4 D1;
  vec4 B0;
  vec4 B1;
  float Fog;
  vec4 T0;
  vec4 T1;
  vec4 T2;
  vec4 T3;
};
noperspective in VertexData g_vtx;
#define vtx g_vtx

out vec4 fragColor;

uniform vec4 fogColor;
float sign1(float x) {
    x *= 255.0;
    return (x-128.0)/127.0;
}
float sign2(float x) {
    x *= 255.0;
    if (x >= 128.0) return (x-255.5)/127.5;
               else return (x+0.5)/127.5;
}
float sign3(float x) {
    x *= 255.0;
    if (x >= 128.0) return (x-256.0)/127.0;
               else return (x)/127.0;
}
vec3 dotmap_zero_to_one(vec3 col) {
    return col;
}
vec3 dotmap_minus1_to_1_d3d(vec3 col) {
    return vec3(sign1(col.r),sign1(col.g),sign1(col.b));
}
vec3 dotmap_minus1_to_1_gl(vec3 col) {
    return vec3(sign2(col.r),sign2(col.g),sign2(col.b));
}
vec3 dotmap_minus1_to_1(vec3 col) {
    return vec3(sign3(col.r),sign3(col.g),sign3(col.b));
}
vec3 dotmap_hilo_1(vec3 col) {
    return col;
}
vec3 dotmap_hilo_hemisphere_d3d(vec3 col) {
    return col;
}
vec3 dotmap_hilo_hemisphere_gl(vec3 col) {
    return col;
}
vec3 dotmap_hilo_hemisphere(vec3 col) {
    return col;
}
uniform ivec4 clipRegion[1];
uniform sampler2DRect texSamp0;
uniform sampler2DRect texSamp1;
uniform vec4 c0_0;
uniform vec4 c0_1;
void main() {
/*  Window-clip (Inclusive) */
bool clipContained = false;
for (int i = 0; i < 1; i++) {
  bvec4 clipTest = bvec4(lessThan(gl_FragCoord.xy, clipRegion[i].xy),
                         greaterThan(gl_FragCoord.xy, clipRegion[i].zw));
  if (!any(clipTest)) {
    clipContained = true;
    break;
  }
}
if (!clipContained) { discard; }
vec4 pD0 = vtx.D0 / vtx.inv_w;
vec4 pD1 = vtx.D1 / vtx.inv_w;
vec4 pB0 = vtx.B0 / vtx.inv_w;
vec4 pB1 = vtx.B1 / vtx.inv_w;
vec4 pFog = vec4(fogColor.rgb, clamp(vtx.Fog / vtx.inv_w, 0.0, 1.0));
vec4 pT0 = vtx.T0 / vtx.inv_w;
vec4 pT1 = vtx.T1 / vtx.inv_w;
vec4 pT2 = vtx.T2 / vtx.inv_w;
vec4 pT3 = vtx.T3 / vtx.inv_w;

vec4 v0 = pD0;
vec4 v1 = pD1;
vec4 t0 = textureProj(texSamp0, pT0.xyw);
vec4 t1 = textureProj(texSamp1, pT1.xyw);
vec4 t2 = vec4(0.0); /* PS_TEXTUREMODES_NONE */
vec4 t3 = vec4(0.0); /* PS_TEXTUREMODES_NONE */
vec4 r1;
vec4 r0;
r0.a = t0.a;
// Stage 0
r1.rgb = clamp(vec3(((t0.rgb * c0_0.rgb) + (t1.rgb * c0_0.aaa))), -1.0, 1.0);
// Stage 1
r0.rgb = clamp(vec3(dot(r1.rgb, c0_1.rgb)), -1.0, 1.0);
r0.a = r0.b;
dot(vec4(0.0).rgb, vec4(0.0).rgb).a = dot(vec4(0.0).rgb, vec4(0.0).rgb).b;
// Stage 2
r1.rgb = clamp(vec3(((r0.a >= 0.5) ? vec3((r1.rgb * (1.0 - clamp(vec4(0.0).rgb, 0.0, 1.0)))) : vec3((vec4(0.0).rgb * vec4(0.0).rgb)))), -1.0, 1.0);
r0.a = clamp((((2.0 * max(r0.a, 0.0) - 1.0) * (1.0 - clamp(vec4(0.0).a, 0.0, 1.0)))), -1.0, 1.0);
// Final Combiner
fragColor.rgb = max(r1.rgb, 0.0) + mix(vec3(max(vec4(0.0).rgb, 0.0)), vec3(max(vec4(0.0).rgb, 0.0)), vec3(max(vec4(0.0).rgb, 0.0)));
fragColor.a = max(r0.a, 0.0);
}


nv2a: fragment shader compilation failed: 0:100(1): error: cannot access field `a' of non-structure / non-vector
0:100(1): error: type mismatch
0:100(39): error: cannot access field `b' of non-structure / non-vector
0:100(39): error: type mismatch

[1]    12153 abort      ./xemu

[abaire]

It'd be interesting to re-test this with #720 which makes some significant changes to the combiner generation. If this is still reproducible, I'd be very interested to look at a log of the pgraph trace around the time of the crash; the vectors being dotted don't make any sense since they're set to the combiner zero constant.

I own this game but I'm getting a crash when attempting to get past the start screen so I can't verify at the moment (could be dump related, HDD image related, or the fact that I'm running it off my dev branch to have more debugging output).

[HadetTheUndying]

It'd be interesting to re-test this with #720 which makes some significant changes to the combiner generation. If this is still reproducible, I'd be very interested to look at a log of the pgraph trace around the time of the crash; the vectors being dotted don't make any sense since they're set to the combiner zero constant.

I own this game but I'm getting a crash when attempting to get past the start screen so I can't verify at the moment (could be dump related, HDD image related, or the fact that I'm running it off my dev branch to have more debugging output).

Can confirm #720 fixes. The game is fully playable and running really well