From 7d07720de13ca0463377d8549181db438ae65c65 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Fri, 23 Nov 2018 08:02:09 -0600
Subject: [PATCH] [JIT] Zero constant propagation for OPCODE_SHL/OPCODE_SHR.

---
 .../cpu/compiler/passes/constant_propagation_pass.cc      | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc b/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
index e44fce425..3db8e99d6 100644
--- a/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
+++ b/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
@@ -618,6 +618,10 @@ bool ConstantPropagationPass::Run(HIRBuilder* builder) {
             v->set_from(i->src1.value);
             v->Shl(i->src2.value);
             i->Remove();
+          } else if (i->src2.value->IsConstantZero()) {
+            auto src1 = i->src1.value;
+            i->Replace(&OPCODE_ASSIGN_info, 0);
+            i->set_src1(src1);
           }
           break;
         case OPCODE_SHR:
@@ -625,6 +629,10 @@ bool ConstantPropagationPass::Run(HIRBuilder* builder) {
             v->set_from(i->src1.value);
             v->Shr(i->src2.value);
             i->Remove();
+          } else if (i->src2.value->IsConstantZero()) {
+            auto src1 = i->src1.value;
+            i->Replace(&OPCODE_ASSIGN_info, 0);
+            i->set_src1(src1);
           }
           break;
         case OPCODE_SHA: