refactor(shader): consolidate 20 inc*_stat methods into inc_fu_stat

[eunseo9311]

Summary

Consolidate 20 near-identical power statistics methods in shader_core_ctx into a single parameterized implementation. No call sites were modified and simulation output is unchanged.

Motivation

shader_core_ctx contained 20 methods (incialu_stat, incfpalu_stat, incsqrt_stat, etc.) that all followed the same three-step pattern:

1. Compute active_count * latency
2. Optionally add inactive lane overhead via inactive_lanes_accesses_sfu() or inactive_lanes_accesses_nonsfu() depending on the execution unit type, gated by gpgpu_clock_gated_lanes
3. Optionally update m_active_exu_threads and m_active_exu_warps

The only differences across all 20 methods were which counter to write, which lane overhead function to call, and whether to update the EXU counters — making this a clear consolidation opportunity.

Changes

shader.h

• Added enum class lane_model { SFU, NON_SFU, NONE } to express the three execution unit categories
• Replaced each method body (~12 lines each) with a single-line delegation to inc_fu_stat()
• Existing public API is fully preserved — zero call site changes required

shader.cc

• Added 16-line implementation of shader_core_ctx::inc_fu_stat()

void shader_core_ctx::inc_fu_stat(double *counter, unsigned active_count,
                                   double latency, lane_model model,
                                   bool update_exu) {
  double access = (double)active_count * latency;
  if (model != lane_model::NONE && !m_config->gpgpu_clock_gated_lanes) {
    access += (model == lane_model::SFU)
                  ? inactive_lanes_accesses_sfu(active_count, latency)
                  : inactive_lanes_accesses_nonsfu(active_count, latency);
  }
  counter[m_sid] += access;
  if (update_exu) {
    m_stats->m_active_exu_threads[m_sid] += active_count;
    m_stats->m_active_exu_warps[m_sid]++;
  }
}

Pattern classification

All 20 methods were verified to fall into exactly four patterns:

Pattern	lane_model	update_exu	Methods
A	NON_SFU	true	incialu, incimul, incimul24, incfpalu, incfpmul, incdpalu, incdpmul (7)
B	SFU	true	incimul32, incidiv, incfpdiv, incdpdiv, incsqrt, inclog, incexp, incsin, inctensor, inctex (10)
C	NON_SFU	false	incmem (1)
D	NONE	false	incsfu, incsp (2)

Stats

• -233 / +47 lines (net: -186 lines)
• 0 call site changes
• All counter types confirmed double * across all 20 methods

Testing

Verified with Rodinia 2.0 hotspot on GTX1080Ti config. All m_num_*_acesses values in gpgpusim.*.log are identical before and after the change.

source setup_environment release && make -j