From e1f31a2da34353e31495275ca4f31deaa43953a1 Mon Sep 17 00:00:00 2001
From: joevt <joevt@shaw.ca>
Date: Tue, 9 Apr 2024 02:17:03 -0700
Subject: [PATCH] poweropcodes: Fix rrib.

It is redundant to test bit 0 of rS and then use bit 0 of rS in the case when bit 0 of rS is set.
In the case when bit 0 of rS is not set, using bit 0 or rS is incorrect since it results in no change of rA.
---
 cpu/ppc/poweropcodes.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/cpu/ppc/poweropcodes.cpp b/cpu/ppc/poweropcodes.cpp
index 9a0df83..2ce1a72 100644
--- a/cpu/ppc/poweropcodes.cpp
+++ b/cpu/ppc/poweropcodes.cpp
@@ -365,11 +365,12 @@ void dppc_interpreter::power_rlmi() {
 template <field_rc rec>
 void dppc_interpreter::power_rrib() {
     ppc_grab_regssab(ppc_cur_instruction);
+    unsigned rot_sh = ppc_result_b & 0x1F;
 
     if (int32_t(ppc_result_d) < 0) {
-        ppc_result_a |= ((ppc_result_d & 0x80000000) >> ppc_result_b);
+        ppc_result_a |= (0x80000000U >> rot_sh);
     } else {
-        ppc_result_a &= ~((ppc_result_d & 0x80000000) >> ppc_result_b);
+        ppc_result_a &= ~(0x80000000U >> rot_sh);
     }
 
     if (rec)