From 1fd621494515d034cc830704e8a765d0929e8ea0 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sat, 5 Jul 2014 17:09:55 -0700
Subject: [PATCH] Improve function range detection.

This improves a pattern like this:

  j endOfLoop;
  li v0, 0;
  startOfLoop:
  addiu v0, v0, 1
endOfLoop:
  bne v0, a0, startOfLoop;
  nop
  jr ra
  nop

Where it jumps to the end of the loop, which only jumps back to the top of
the loop.  This might misdetect a few cases of tail recursion, but only
when the funcs are right next to each other.

Also, stops scanning at a jr ra, which was causing funcs to be incorrectly
long in cases.
---
 Core/MIPS/MIPSAnalyst.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/Core/MIPS/MIPSAnalyst.cpp b/Core/MIPS/MIPSAnalyst.cpp
index 407f4ae7d8..263ac0d89e 100644
--- a/Core/MIPS/MIPSAnalyst.cpp
+++ b/Core/MIPS/MIPSAnalyst.cpp
@@ -201,7 +201,7 @@ static const HardHashTableEntry hardcodedHashes[] = {
 	{ 0x52d5141545a75eda, 60, "dl_write_clutformat", },
 	{ 0x530cbe1ce9b45d58, 108, "dl_write_light_vector", },
 	{ 0x53c9aa23504a630f, 96, "vmmul_q_5", },
-	{ 0x54015ccbcbc75374, 24, "strlen", },
+	{ 0x54015ccbcbc75374, 24, "strlen", }, // Metal Gear Solid: Peace Walker demo
 	{ 0x5550d87a851c218c, 168, "dl_write_viewport", },
 	{ 0x55c1294280bfade0, 88, "dl_write_blend_fixed", },
 	{ 0x56c9929e8c8c5768, 24, "fabsf", },
@@ -413,7 +413,7 @@ static const HardHashTableEntry hardcodedHashes[] = {
 	{ 0xfb4253a1d9d9df9f, 20, "isnanf", },
 	{ 0xfd34a9ad94fa6241, 76, "__extendsfdf2", },
 	{ 0xfe4f0280240008e9, 28, "vavg_q", },
-	{ 0xfe5dd338ab862291, 216, "memset", },
+	{ 0xfe5dd338ab862291, 216, "memset", }, // Metal Gear Solid: Peace Walker demo
 	{ 0xffc8f5f8f946152c, 192, "dl_write_light_color", },
 };
 
@@ -755,6 +755,9 @@ skip:
 					closestJumpbackTarget = target;
 				}
 			}
+			if (aheadOp == MIPS_MAKE_JR_RA()) {
+				break;
+			}
 		}
 
 		if (closestJumpbackAddr != INVALIDTARGET && furthestJumpbackAddr == INVALIDTARGET) {
@@ -846,7 +849,8 @@ skip:
 					}
 
 					// A jump later.  Probably tail, but let's check if it jumps back.
-					u32 knownEnd = furthestBranch == 0 ? addr : furthestBranch;
+					// We use + 8 here in case it jumps right back to the delay slot.  We'll consider that inside the func.
+					u32 knownEnd = furthestBranch == 0 ? addr + 8 : furthestBranch;
 					u32 jumpback = ScanAheadForJumpback(sureTarget, currentFunction.start, knownEnd);
 					if (jumpback != INVALIDTARGET && jumpback > addr && jumpback > knownEnd) {
 						furthestBranch = jumpback;