From 21f9e9da092ddd96fe9f149660a5bf4f676c8413 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Tue, 18 Dec 2018 19:54:12 -0300
Subject: [PATCH] shader_decode: Implement HSETP2

---
 .../shader/decode/half_set_predicate.cpp      | 38 ++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/video_core/shader/decode/half_set_predicate.cpp b/src/video_core/shader/decode/half_set_predicate.cpp
index 5fe123ea52..d7d63d50a4 100644
--- a/src/video_core/shader/decode/half_set_predicate.cpp
+++ b/src/video_core/shader/decode/half_set_predicate.cpp
@@ -11,12 +11,48 @@ namespace VideoCommon::Shader {
 
 using Tegra::Shader::Instruction;
 using Tegra::Shader::OpCode;
+using Tegra::Shader::Pred;
 
 u32 ShaderIR::DecodeHalfSetPredicate(BasicBlock& bb, u32 pc) {
     const Instruction instr = {program_code[pc]};
     const auto opcode = OpCode::Decode(instr);
 
-    UNIMPLEMENTED();
+    UNIMPLEMENTED_IF(instr.hsetp2.ftz != 0);
+
+    Node op_a = GetRegister(instr.gpr8);
+    op_a = GetOperandAbsNegHalf(op_a, instr.hsetp2.abs_a, instr.hsetp2.negate_a);
+
+    const Node op_b = [&]() {
+        switch (opcode->get().GetId()) {
+        case OpCode::Id::HSETP2_R:
+            return GetOperandAbsNegHalf(GetRegister(instr.gpr20), instr.hsetp2.abs_a,
+                                        instr.hsetp2.negate_b);
+        default:
+            UNREACHABLE();
+            return Immediate(0);
+        }
+    }();
+
+    // We can't use the constant predicate as destination.
+    ASSERT(instr.hsetp2.pred3 != static_cast<u64>(Pred::UnusedIndex));
+
+    const Node second_pred = GetPredicate(instr.hsetp2.pred39, instr.hsetp2.neg_pred != 0);
+
+    const OperationCode combiner = GetPredicateCombiner(instr.hsetp2.op);
+
+    MetaHalfArithmetic meta = {
+        false, {instr.hsetp2.type_a, instr.hsetp2.type_b}, instr.hsetp2.h_and != 0};
+    const Node first_pred = GetPredicateComparisonHalf(instr.hsetp2.cond, meta, op_a, op_b);
+
+    // Set the primary predicate to the result of Predicate OP SecondPredicate
+    const Node value = Operation(combiner, first_pred, second_pred);
+    SetPredicate(bb, instr.hsetp2.pred3, value);
+
+    if (instr.hsetp2.pred0 != static_cast<u64>(Pred::UnusedIndex)) {
+        // Set the secondary predicate to the result of !Predicate OP SecondPredicate, if enabled
+        const Node negated_pred = Operation(OperationCode::LogicalNegate, first_pred);
+        SetPredicate(bb, instr.hsetp2.pred0, Operation(combiner, negated_pred, second_pred));
+    }
 
     return pc;
 }