aco: compact aco::span<T> to use uint16_t offset and size instead of pointer and size_t.

This reduces the size of the Instruction base class
from 40 bytes to 16 bytes. No pipelinedb changes.

Reviewed-by: Rhys Perry <[email protected]>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3332>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3332>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/amd/compiler/aco_ir.h b/src/amd/compiler/aco_ir.h
index 388bf064000..1ee31d23702 100644
--- a/src/amd/compiler/aco_ir.h
+++ b/src/amd/compiler/aco_ir.h
@@ -929,8 +929,10 @@ T* create_instruction(aco_opcode opcode, Format format, uint32_t num_operands, u
    inst->opcode = opcode;
    inst->format = format;
 
-   inst->operands = aco::span<Operand>((Operand*)(data + sizeof(T)), num_operands);
-   inst->definitions = aco::span<Definition>((Definition*)inst->operands.end(), num_definitions);
+   uint16_t operands_offset = data + sizeof(T) - (char*)&inst->operands;
+   inst->operands = aco::span<Operand>(operands_offset, num_operands);
+   uint16_t definitions_offset = (char*)inst->operands.end() - (char*)&inst->definitions;
+   inst->definitions = aco::span<Definition>(definitions_offset, num_definitions);
 
    return inst;
 }