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aco: split self-intersecting copies instead of swapping 

Example situation:
v1 = {v0.hi, v1.lo}
v0.hi = v1.hi

The 4-byte copy's definition is completely used, but swapping it makes no
sense. We have to split it to generate correct code:
swap(v0.hi, v1.lo)
swap(v0.hi, v1.hi)

Found in dEQP-VK.spirv_assembly.type.vec3.i16.constant_composite_vert

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4772>
This commit is contained in:
Rhys Perry 2020-04-27 20:13:53 +01:00 committed by Marge Bot
parent be4a34966c
commit 09c584caeb
1 changed files with 33 additions and 0 deletions
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33
src/amd/compiler/aco_lower_to_hw_instr.cpp
View File

@ -1091,6 +1091,39 @@ void handle_operands(std::map<PhysReg, copy_operation>& copy_map, lower_context*
/* to resolve the cycle, we have to swap the src reg with the dst reg */
copy_operation swap = it->second;
/* if this is self-intersecting, we have to split it because
* self-intersecting swaps don't make sense */
PhysReg lower = swap.def.physReg();
PhysReg higher = swap.op.physReg();
if (lower.reg_b > higher.reg_b)
std::swap(lower, higher);
if (higher.reg_b - lower.reg_b < (int)swap.bytes) {
unsigned offset = higher.reg_b - lower.reg_b;
RegType type = swap.def.regClass().type();
copy_operation middle;
lower.reg_b += offset;
higher.reg_b += offset;
middle.bytes = swap.bytes - offset * 2;
memcpy(middle.uses, swap.uses + offset, middle.bytes);
middle.op = Operand(lower, RegClass::get(type, middle.bytes));
middle.def = Definition(higher, RegClass::get(type, middle.bytes));
copy_map[higher] = middle;
copy_operation end;
lower.reg_b += middle.bytes;
higher.reg_b += middle.bytes;
end.bytes = swap.bytes - (offset + middle.bytes);
memcpy(end.uses, swap.uses + offset + middle.bytes, end.bytes);
end.op = Operand(lower, RegClass::get(type, end.bytes));
end.def = Definition(higher, RegClass::get(type, end.bytes));
copy_map[higher] = end;
memset(swap.uses + offset, 0, swap.bytes - offset);
swap.bytes = offset;
}
do_swap(ctx, bld, swap, preserve_scc, pi);
/* remove from map */