1 files changed, 24 insertions, 2 deletions
diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_image.cpp b/src/shader_recompiler/backend/spirv/emit_spirv_image.cpp
index 2f925cc3e..7d7c0627e 100644
--- a/src/shader_recompiler/backend/spirv/emit_spirv_image.cpp
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_image.cpp
@@ -470,8 +470,30 @@ void EmitImageWrite(EmitContext& ctx, IR::Inst* inst, const IR::Value& index, Id
     ctx.OpImageWrite(Image(ctx, index, info), coords, color);
 }
 
-Id EmitIsTextureScaled([[maybe_unused]] EmitContext& ctx, [[maybe_unused]] const IR::Value& index) {
-    return ctx.false_value;
+Id EmitIsTextureScaled(EmitContext& ctx, const IR::Value& index) {
+    const Id push_constant_u32{ctx.TypePointer(spv::StorageClass::PushConstant, ctx.U32[1])};
+    const Id member_index{ctx.Const(ctx.rescaling_textures_member_index)};
+    Id bit{};
+    if (index.IsImmediate()) {
+        // Use BitwiseAnd instead of BitfieldExtract for better codegen on Nvidia OpenGL.
+        // LOP32I.NZ is used to set the predicate rather than BFE+ISETP.
+        const u32 index_value{index.U32()};
+        const Id word_index{ctx.Const(index_value / 32)};
+        const Id bit_index_mask{ctx.Const(1u << (index_value % 32))};
+        const Id pointer{ctx.OpAccessChain(push_constant_u32, ctx.rescaling_push_constants,
+                                           member_index, word_index)};
+        const Id word{ctx.OpLoad(ctx.U32[1], pointer)};
+        bit = ctx.OpBitwiseAnd(ctx.U32[1], word, bit_index_mask);
+    } else {
+        const Id index_value{ctx.Def(index)};
+        const Id word_index{ctx.OpShiftRightArithmetic(ctx.U32[1], index_value, ctx.Const(5u))};
+        const Id pointer{ctx.OpAccessChain(push_constant_u32, ctx.rescaling_push_constants,
+                                           member_index, word_index)};
+        const Id word{ctx.OpLoad(ctx.U32[1], pointer)};
+        const Id bit_index{ctx.OpBitwiseAnd(ctx.U32[1], index_value, ctx.Const(31u))};
+        bit = ctx.OpBitFieldUExtract(ctx.U32[1], index_value, bit_index, ctx.Const(1u));
+    }
+    return ctx.OpINotEqual(ctx.U1, bit, ctx.u32_zero_value);
 }
 
 } // namespace Shader::Backend::SPIRV