I have enabled verbose debug output from OpenGL.
When linking my GL shader on Alderlake GT1 (OS: Ubuntu) the driver complains with:
[API][Performance]{Notification}: SIMD32 shader inefficient
Note: the app works as intended, but I want to understand why my program is marked as inefficient?
Vertex Shader code:
#version 150
in mediump vec2 position;
out lowp vec4 clr;
uniform lowp vec4 colour;
uniform mediump float invaspect;
uniform mediump vec2 rotx;
uniform mediump vec2 roty;
uniform mediump vec2 translation;
void main()
{
gl_Position.x = rotx.x * position.x + roty.x * position.y + translation.x;
gl_Position.y = rotx.y * position.x + roty.y * position.y + translation.y;
gl_Position.x *= invaspect;
gl_Position.z = 1.0;
gl_Position.w = 1.0;
clr = colour;
}
Fragment Shader code:
#version 150
in lowp vec4 clr;
out lowp vec4 fragColor;
void main()
{
fragColor = clr;
}
More output:
WRN [Shader Compiler][Other]{Notification}: VS SIMD8 shader: 10 inst, 0 loops, 39 cycles, 0:0 spills:fills, 1 sends, scheduled with mode top-down, Promoted 0 constants, compacted 160 to 128 bytes.
WRN [API][Performance]{Notification}: SIMD32 shader inefficient
WRN [Shader Compiler][Other]{Notification}: FS SIMD8 shader: 5 inst, 0 loops, 20 cycles, 0:0 spills:fills, 1 sends, scheduled with mode top-down, Promoted 0 constants, compacted 80 to 48 bytes.
WRN [Shader Compiler][Other]{Notification}: FS SIMD16 shader: 5 inst, 0 loops, 28 cycles, 0:0 spills:fills, 1 sends, scheduled with mode top-down, Promoted 0 constants, compacted 80 to 48 bytes.
Loaded program Main as handle 9 in slot 2
