From ab158fd4d763e1b51ccc32bde5ab19f4e7cb0a1d Mon Sep 17 00:00:00 2001
From: Lander Gallastegi <landergallastegi@gmail.com>
Date: Mon, 7 Apr 2025 23:04:34 +0200
Subject: [PATCH] Don't reuse stack space for now

---
 .../backend/asm_x64/x64_emit_context.cpp      | 23 +++----------------
 .../backend/asm_x64/x64_emit_context.h        |  2 --
 2 files changed, 3 insertions(+), 22 deletions(-)

diff --git a/src/shader_recompiler/backend/asm_x64/x64_emit_context.cpp b/src/shader_recompiler/backend/asm_x64/x64_emit_context.cpp
index ee104fe89..7d8449f53 100644
--- a/src/shader_recompiler/backend/asm_x64/x64_emit_context.cpp
+++ b/src/shader_recompiler/backend/asm_x64/x64_emit_context.cpp
@@ -167,12 +167,7 @@ void EmitContext::SpillInst(RegAllocContext& ctx, const ActiveInstInterval& inte
                             ActiveIntervalList& active_intervals) {
     const auto get_operand = [&](IR::Inst* inst) -> Operand {
         size_t current_sp = inst_stack_space;
-        if (ctx.free_stack_slots.empty()) {
-            inst_stack_space += 8;
-        } else {
-            current_sp += ctx.free_stack_slots.back();
-            ctx.free_stack_slots.pop_back();
-        }
+        inst_stack_space += 8;
         switch (GetRegBytesOfType(IR::Value(inst))) {
         case 1:
             return byte[r11 + current_sp];
@@ -192,14 +187,12 @@ void EmitContext::SpillInst(RegAllocContext& ctx, const ActiveInstInterval& inte
         [](const ActiveInstInterval& a, const ActiveInstInterval& b) { return a.end < b.end; });
     if (spill_candidate == active_intervals.end() || spill_candidate->end <= interval.start) {
         inst_to_operands[interval.inst][interval.component] = get_operand(interval.inst);
-        ctx.active_spill_intervals.push_back(interval);
     } else {
         Operands& operands = inst_to_operands[spill_candidate->inst];
-        Reg reg = operands[spill_candidate->component].Reg();
+        OperandHolder op = operands[spill_candidate->component];
         inst_to_operands[interval.inst][interval.component] =
-            reg.isXMM() ? reg : ResizeRegToType(reg, interval.inst);
+            op.IsXmm() ? op : ResizeRegToType(op.Reg(), interval.inst);
         operands[spill_candidate->component] = get_operand(spill_candidate->inst);
-        ctx.active_spill_intervals.push_back(*spill_candidate);
         *spill_candidate = interval;
     }
 }
@@ -304,16 +297,6 @@ void EmitContext::AllocateRegisters() {
                 ++it;
             }
         }
-        for (auto it = ctx.active_spill_intervals.begin();
-             it != ctx.active_spill_intervals.end();) {
-            if (it->end < interval.start) {
-                const Address& addr = inst_to_operands[it->inst][it->component].Mem();
-                ctx.free_stack_slots.push_back(addr.getDisp());
-                it = ctx.active_spill_intervals.erase(it);
-            } else {
-                ++it;
-            }
-        }
         u8 num_components = GetNumComponentsOfType(interval.inst);
         bool is_floating = IsFloatingType(interval.inst);
         auto& operands = inst_to_operands[interval.inst];
diff --git a/src/shader_recompiler/backend/asm_x64/x64_emit_context.h b/src/shader_recompiler/backend/asm_x64/x64_emit_context.h
index ce9921233..ad0e1da6d 100644
--- a/src/shader_recompiler/backend/asm_x64/x64_emit_context.h
+++ b/src/shader_recompiler/backend/asm_x64/x64_emit_context.h
@@ -154,10 +154,8 @@ private:
     struct RegAllocContext {
         boost::container::static_vector<Xbyak::Reg64, NumGPRegs> free_gp_regs;
         boost::container::static_vector<Xbyak::Xmm, NumXmmRegs> free_xmm_regs;
-        boost::container::small_vector<size_t, 8> free_stack_slots;
         ActiveIntervalList active_gp_intervals;
         ActiveIntervalList active_xmm_intervals;
-        ActiveIntervalList active_spill_intervals;
     };
 
     using FlatInstList = boost::container::small_vector<IR::Inst*, 64>;