GPU Occupancy Calculator

Write a C program that calculates GPU occupancy given kernel resource constraints.

Requirements:

• Define hardware constants: REGISTERS_PER_SM = 65536, MAX_WARPS_PER_SM = 48, SHARED_PER_SM = 49152 bytes, WARP_SIZE = 32
• Read from stdin: registers_per_thread, shared_memory_per_block, threads_per_block
• Calculate warps_per_block = threads_per_block / WARP_SIZE (round up)
• Calculate max blocks by registers: REGISTERS_PER_SM / (registers_per_thread * threads_per_block)
• Calculate max blocks by shared memory: SHARED_PER_SM / shared_memory_per_block
• Calculate max blocks by warps: MAX_WARPS_PER_SM / warps_per_block
• The actual blocks per SM is the minimum of these three limits
• Calculate active warps = blocks_per_sm * warps_per_block
• Calculate occupancy percentage = (active_warps / MAX_WARPS_PER_SM) * 100
• Print the limiting factor (registers, shared memory, or warps)
• Test with three configurations: (a) registers=32, shared=4096, threads=256 (should be warp-limited or high occupancy) (b) registers=128, shared=8192, threads=512 (should be register-limited) (c) registers=64, shared=24576, threads=256 (should be shared-memory-limited)
• Print a note explaining whether higher occupancy would help this kernel