From f14db9b220e84296c8c3f94a02b8131f05549d86 Mon Sep 17 00:00:00 2001
From: Shinmegumi <shinmegumi@eden-emu.dev>
Date: Fri, 1 Aug 2025 19:30:26 +0200
Subject: [PATCH] revert 7b9798f84298de47066d429fd452ddfec1492fe6

revert Revert "[shader_recompiler/Maxwell] Unstub ISBERD completely (#160)"

This reverts commit 3f12ae1e6eddc9848074a5a6b9b1bf01ab2a6957.

Found that this was not the cause of the performance issue on this PR. Reverting so it can be tested once fix for the slowdown can be merged and this PR rebased.
---
 .../impl/internal_stage_buffer_entry_read.cpp | 51 +++++++++++++++++--
 1 file changed, 47 insertions(+), 4 deletions(-)

diff --git a/src/shader_recompiler/frontend/maxwell/translate/impl/internal_stage_buffer_entry_read.cpp b/src/shader_recompiler/frontend/maxwell/translate/impl/internal_stage_buffer_entry_read.cpp
index 59ca4b15a3..d71c65069b 100644
--- a/src/shader_recompiler/frontend/maxwell/translate/impl/internal_stage_buffer_entry_read.cpp
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/internal_stage_buffer_entry_read.cpp
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -37,16 +40,56 @@ void TranslatorVisitor::ISBERD(u64 insn) {
     } const isberd{insn};
 
     if (isberd.skew != 0) {
-        throw NotImplementedException("SKEW");
+        IR::U32 current_lane_id{ir.LaneId()};
+        IR::U32 result{ir.IAdd(X(isberd.src_reg), current_lane_id)};
+        X(isberd.dest_reg, result);
     }
     if (isberd.o != 0) {
-        throw NotImplementedException("O");
+        IR::U32 address{};
+        IR::F32 result{};
+        if (isberd.src_reg_num == 0xFF) {
+            address = ir.Imm32(isberd.imm);
+            result = ir.GetAttributeIndexed(address);
+        } else {
+            IR::U32 offset = ir.Imm32(isberd.imm);
+            address = ir.IAdd(X(isberd.src_reg), offset);
+            result = ir.GetAttributeIndexed(address);
+        }
+        X(isberd.dest_reg, ir.BitCast<IR::U32>(result));
     }
     if (isberd.mode != Mode::Default) {
-        throw NotImplementedException("Mode {}", isberd.mode.Value());
+        IR::F32 result{};
+        IR::U32 index{};
+        if (isberd.src_reg_num == 0xFF) {
+            index = ir.Imm32(isberd.imm);
+        } else {
+            index = ir.IAdd(X(isberd.src_reg), ir.Imm32(isberd.imm));
+        }
+
+        switch (static_cast<u64>(isberd.mode.Value())) {
+        case static_cast<u64>(Mode::Patch):
+            result = ir.GetPatch(index.Patch());
+            break;
+        case static_cast<u64>(Mode::Prim):
+            result = ir.GetAttribute(index.Attribute());
+            break;
+        case static_cast<u64>(Mode::Attr):
+            result = ir.GetAttributeIndexed(index);
+            break;
+        }
+        X(isberd.dest_reg, ir.BitCast<IR::U32>(result));
     }
     if (isberd.shift != Shift::Default) {
-        throw NotImplementedException("Shift {}", isberd.shift.Value());
+        IR::U32 result{};
+        switch (static_cast<u64>(isberd.shift.Value())) {
+        case static_cast<u64>(Shift::U16):
+            result = ir.ShiftLeftLogical(result, static_cast<IR::U32>(ir.Imm16(1)));
+            break;
+        case static_cast<u64>(Shift::B32):
+            result = ir.ShiftLeftLogical(result, ir.Imm32(1));
+            break;
+        }
+        X(isberd.dest_reg, result);
     }
     //LOG_DEBUG(Shader, "(STUBBED) called {}", insn);
     if (isberd.src_reg_num == 0xFF) {