[shader_recompiler] Rewrite ISBERD

6 months ago · efe9c30997
3 changed files with 85 additions and 94 deletions
--- a/src/shader_recompiler/frontend/maxwell/translate/impl/impl.cpp
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/impl.cpp
@ -271,40 +271,4 @@ void TranslatorVisitor::ResetOFlag() {
    SetOFlag(ir.Imm1(false));
 }

-IR::U32 TranslatorVisitor::apply_ISBERD_shift(IR::U32 result, Isberd::Shift shift_value) {
-    if (shift_value != Isberd::Shift::Default) {
-        return ir.ShiftLeftLogical(result, ir.Imm32(1));
-    }
-    return result;
-}
-
-IR::U32 TranslatorVisitor::apply_ISBERD_size_read(IR::U32 address, Isberd::SZ sz) {
-    switch (sz) {
-    case Isberd::SZ::U8:
-        return ir.LoadGlobalU8(ir.UConvert(64, address));
-    case Isberd::SZ::U16:
-        return ir.LoadGlobalU16(ir.UConvert(64, address));
-    case Isberd::SZ::U32:
-    case Isberd::SZ::F32:
-        return ir.LoadGlobal32(ir.UConvert(64, address));
-    default:
-        UNREACHABLE();
-    }
-}
-
-IR::U32 TranslatorVisitor::compute_ISBERD_address(IR::Reg src_reg, u32 src_reg_num, u32 imm, u64 skew_value) {
-    IR::U32 address{};
-    if (src_reg_num == 0xFF) {
-        address = ir.Imm32(imm);
-    } else {
-        auto offset = ir.Imm32(imm);
-        address = ir.IAdd(X(src_reg), offset);
-        if (skew_value != 0) {
-            address = ir.IAdd(address, ir.LaneId());
-        }
-    }
-
-    return address;
-};
-
 } // namespace Shader::Maxwell
--- a/src/shader_recompiler/frontend/maxwell/translate/impl/impl.h
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/impl.h
@ -56,30 +56,6 @@ enum class FPCompareOp : u64 {
    T,
 };

-namespace Isberd {
-enum class Mode : u64 {
-    Default,
-    Patch,
-    Prim,
-    Attr,
-};
-
-enum class Shift : u64 {
-    Default,
-    U16,
-    B32,
-};
-
-enum class SZ : u64 {
-    U8,
-    U16,
-    U32,
-    F32,
-};
-
-} // namespace Isberd
-
-
 class TranslatorVisitor {
 public:
    explicit TranslatorVisitor(Environment& env_, IR::Block& block) : env{env_}, ir(block) {}
@ -408,12 +384,6 @@ public:
    void ResetSFlag();
    void ResetCFlag();
    void ResetOFlag();
-
-private:
-    // Helper functions for various translator visitors
-    IR::U32 apply_ISBERD_shift(IR::U32 result, Isberd::Shift shift_value);
-    IR::U32 apply_ISBERD_size_read(IR::U32 address, Isberd::SZ sz_value);
-    IR::U32 compute_ISBERD_address(IR::Reg src_reg, u32 src_reg_num, u32 imm, u64 skew_value);
 };

 } // namespace Shader::Maxwell
--- 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
@ -9,9 +9,52 @@
 #include "shader_recompiler/frontend/maxwell/translate/impl/impl.h"

 namespace Shader::Maxwell {
+namespace {
+enum class Mode : u64 {
+    Default,
+    Patch,
+    Prim,
+    Attr,
+};
+
+enum class SZ : u64 {
+    U8,
+    U16,
+    U32,
+    F32
+};
+
+enum class Shift : u64 {
+    Default,
+    U16,
+    B32,
+};
+
+IR::U32 scaleIndex(IR::IREmitter& ir, IR::U32 index, Shift shift) {
+    switch (shift) {
+    case Shift::Default: return index;
+    case Shift::U16:     return ir.ShiftLeftLogical(index, ir.Imm32(1));
+    case Shift::B32:     return ir.ShiftLeftLogical(index, ir.Imm32(2));
+    default:             UNREACHABLE();
+    }
+}
+
+IR::U32 skewBytes(IR::IREmitter& ir, SZ sizeRead) {
+    const IR::U32 lane = ir.LaneId();
+    switch (sizeRead) {
+    case SZ::U8:  return lane;
+    case SZ::U16: return ir.ShiftLeftLogical(lane, ir.Imm32(1));
+    case SZ::U32:
+    case SZ::F32: return ir.ShiftLeftLogical(lane, ir.Imm32(2));
+    default:      UNREACHABLE();
+    }
+}
+
+} // Anonymous namespace

-// Valid only for GS, TI, VS and trap
 void TranslatorVisitor::ISBERD(u64 insn) {
+    LOG_DEBUG(Shader, "called with insn={:#X}", insn);
+
    union {
        u64 raw;
        BitField<0, 8, IR::Reg> dest_reg;
@ -20,49 +63,63 @@ void TranslatorVisitor::ISBERD(u64 insn) {
        BitField<24, 8, u32> imm;
        BitField<31, 1, u64> skew;
        BitField<32, 1, u64> o;
-        BitField<33, 2, Isberd::Mode> mode;
-        BitField<36, 4, Isberd::SZ> sz;
-        BitField<47, 2, Isberd::Shift> shift;
+        BitField<33, 2, Mode> mode;
+        BitField<36, 4, SZ> sz;
+        BitField<47, 2, Shift> shift;
    } const isberd{insn};

-    auto address = compute_ISBERD_address(isberd.src_reg, isberd.src_reg_num, isberd.imm, isberd.skew);
-    if (isberd.o != 0) {
-        auto result = apply_ISBERD_size_read(address, isberd.sz.Value());
-        X(isberd.dest_reg, apply_ISBERD_shift(result, isberd.shift.Value()));
+    IR::U32 index{};
+    if (isberd.src_reg_num.Value() == 0xFF) {
+        index = ir.Imm32(isberd.imm.Value());
+    } else {
+        const IR::U32 scaledIndex = scaleIndex(ir, X(isberd.src_reg.Value()), isberd.shift.Value());
+        index = ir.IAdd(scaledIndex, ir.Imm32(isberd.imm.Value()));
+    }
+
+    if (isberd.o.Value()) {
+        if (isberd.skew.Value()) {
+            index = ir.IAdd(index, skewBytes(ir, isberd.sz.Value()));
+        }
+
+        const IR::U64 index64 = ir.UConvert(64, index);
+        IR::U32 globalLoaded{};
+        switch (isberd.sz.Value()) {
+        case SZ::U8:  globalLoaded = ir.LoadGlobalU8 (index64); break;
+        case SZ::U16: globalLoaded = ir.LoadGlobalU16(index64); break;
+        case SZ::U32:
+        case SZ::F32: globalLoaded = ir.LoadGlobal32(index64);  break;
+        default:      UNREACHABLE();
+        }
+        X(isberd.dest_reg.Value(), globalLoaded);

        return;
    }

-    if (isberd.mode != Isberd::Mode::Default) {
-        IR::F32 result_f32{};
+    if (isberd.mode.Value() != Mode::Default) {
+        if (isberd.skew.Value()) {
+            index = ir.IAdd(index, skewBytes(ir, SZ::U32));
+        }
+
+        IR::F32 float_index{};
        switch (isberd.mode.Value()) {
-        case Isberd::Mode::Patch:
-            result_f32 = ir.GetPatch(address.Patch());
-            break;
-        case Isberd::Mode::Prim:
-            result_f32 = ir.GetAttribute(address.Attribute());
-            break;
-        case Isberd::Mode::Attr:
-            result_f32 = ir.GetAttributeIndexed(address);
-            break;
-        default:
-            UNREACHABLE();
+        case Mode::Patch: float_index = ir.GetPatch(index.Patch());             break;
+        case Mode::Prim:  float_index = ir.GetAttribute(index.Attribute());     break;
+        case Mode::Attr:  float_index = ir.GetAttributeIndexed(index);          break;
+        default:          UNREACHABLE();
        }
+        X(isberd.dest_reg.Value(), ir.BitCast<IR::U32>(float_index));

-        auto result_u32 = ir.BitCast<IR::U32>(result_f32);
-        X(isberd.dest_reg, apply_ISBERD_shift(result_u32, isberd.shift.Value()));
        return;
    }

-    if (isberd.skew != 0) {
-        auto result = ir.IAdd(X(isberd.src_reg), ir.LaneId());
-        X(isberd.dest_reg, result);
+    if (isberd.skew.Value()) {
+        X(isberd.dest_reg.Value(), ir.IAdd(X(isberd.src_reg.Value()), ir.LaneId()));

        return;
    }

-    // Fallback if nothing else applies
-    X(isberd.dest_reg, X(isberd.src_reg));
+    // Fallback copy
+    X(isberd.dest_reg.Value(), X(isberd.src_reg.Value()));
 }

 } // namespace Shader::Maxwell