From 3a63fa0477ea8297c80133d35494e1dfdc012f95 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Tue, 9 Mar 2021 17:14:57 -0300
Subject: shader: Partial implementation of LDC

---
 .../backend/spirv/emit_spirv_context_get_set.cpp   | 56 +++++++++++++++++++---
 1 file changed, 50 insertions(+), 6 deletions(-)

(limited to 'src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp')

diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp b/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
index eb9c01c5a..125b58cf7 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp
@@ -30,17 +30,61 @@ void EmitGetGotoVariable(EmitContext&) {
     throw NotImplementedException("SPIR-V Instruction");
 }
 
-Id EmitGetCbuf(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+static Id GetCbuf(EmitContext& ctx, Id result_type, Id UniformDefinitions::*member_ptr,
+                  u32 element_size, const IR::Value& binding, const IR::Value& offset) {
     if (!binding.IsImmediate()) {
         throw NotImplementedException("Constant buffer indexing");
     }
+    const Id cbuf{ctx.cbufs[binding.U32()].*member_ptr};
+    const Id uniform_type{ctx.uniform_types.*member_ptr};
     if (!offset.IsImmediate()) {
-        throw NotImplementedException("Variable constant buffer offset");
+        Id index{ctx.Def(offset)};
+        if (element_size > 1) {
+            const u32 log2_element_size{static_cast<u32>(std::countr_zero(element_size))};
+            const Id shift{ctx.Constant(ctx.U32[1], log2_element_size)};
+            index = ctx.OpShiftRightArithmetic(ctx.U32[1], ctx.Def(offset), shift);
+        }
+        const Id access_chain{ctx.OpAccessChain(uniform_type, cbuf, ctx.u32_zero_value, index)};
+        return ctx.OpLoad(result_type, access_chain);
     }
-    const Id imm_offset{ctx.Constant(ctx.U32[1], offset.U32() / 4)};
-    const Id cbuf{ctx.cbufs[binding.U32()]};
-    const Id access_chain{ctx.OpAccessChain(ctx.uniform_u32, cbuf, ctx.u32_zero_value, imm_offset)};
-    return ctx.OpLoad(ctx.U32[1], access_chain);
+    if (offset.U32() % element_size != 0) {
+        throw NotImplementedException("Unaligned immediate constant buffer load");
+    }
+    const Id imm_offset{ctx.Constant(ctx.U32[1], offset.U32() / element_size)};
+    const Id access_chain{ctx.OpAccessChain(uniform_type, cbuf, ctx.u32_zero_value, imm_offset)};
+    return ctx.OpLoad(result_type, access_chain);
+}
+
+Id EmitGetCbufU8(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    const Id load{GetCbuf(ctx, ctx.U8, &UniformDefinitions::U8, sizeof(u8), binding, offset)};
+    return ctx.OpUConvert(ctx.U32[1], load);
+}
+
+Id EmitGetCbufS8(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    const Id load{GetCbuf(ctx, ctx.S8, &UniformDefinitions::S8, sizeof(s8), binding, offset)};
+    return ctx.OpSConvert(ctx.U32[1], load);
+}
+
+Id EmitGetCbufU16(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    const Id load{GetCbuf(ctx, ctx.U16, &UniformDefinitions::U16, sizeof(u16), binding, offset)};
+    return ctx.OpUConvert(ctx.U32[1], load);
+}
+
+Id EmitGetCbufS16(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    const Id load{GetCbuf(ctx, ctx.S16, &UniformDefinitions::S16, sizeof(s16), binding, offset)};
+    return ctx.OpSConvert(ctx.U32[1], load);
+}
+
+Id EmitGetCbufU32(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    return GetCbuf(ctx, ctx.U32[1], &UniformDefinitions::U32, sizeof(u32), binding, offset);
+}
+
+Id EmitGetCbufF32(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    return GetCbuf(ctx, ctx.F32[1], &UniformDefinitions::F32, sizeof(f32), binding, offset);
+}
+
+Id EmitGetCbufU64(EmitContext& ctx, const IR::Value& binding, const IR::Value& offset) {
+    return GetCbuf(ctx, ctx.U64, &UniformDefinitions::U64, sizeof(u64), binding, offset);
 }
 
 void EmitGetAttribute(EmitContext&) {
-- 
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