GPU/Shader Instruction Set: Difference between revisions

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 a0.x and a0.y are set manually through the MOVA instruction by rounding a float value to integer precision. Hence, they may take negative values. The way out-of-bounds values behave when reading uniforms is as follows:
-* If the value is out of byte bounds (less than -128 or greater than 127), the result is the vector (0, 0, 0, 0).
+* If the offset is out of byte bounds (less than -128 or greater than 127), the offset is not applied (treated as 0).
-* If the value without its sign bit (value & 0x7F) is greater than 95, the result is the vector (1, 1, 1, 1).
+* The offset is added to the constant register index and masked by 0x7F.
-* Otherwise, the index of the resulting uniform value is the value without its sign bit (value & 0x7F).
+* If the resulting index is greater than 95, the result is (1, 1, 1, 1).
+* Otherwise, the result is the value at the indexed constant register.
 aL can only be set indirectly by the LOOP instruction. It is still accessible and valid after exiting a LOOP block, though.