The OpenGL specifications for bitfieldExtract() says:
The result will be undefined if <offset> or <bits> is negative, or if
the sum of <offset> and <bits> is greater than the number of bits
used to store the operand.
Therefore passing bits=32, offset=0 is legal and defined in GLSL.
But the earlier SM5 ubfe/ibfe opcodes are specified to accept a bitfield width
ranging from 0-31. As such, Intel and AMD instructions read only the low 5 bits
of the width operand, making them not able to implement the GLSL-specified
behavior directly.
This commit adds ubfe/ibfe operations from SM5 and a lowering pass for
bitfield_extract to to handle the trivial case of <bits> = 32 as
bitfieldExtract:
bits > 31 ? value : bfe(value, offset, bits)
Fixes:
ES31-CTS.shader_bitfield_operation.bitfieldExtract.uvec3_0
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92595
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Tested-by: Marta Lofstedt <marta.lofstedt@intel.com>
b82e26a6a4