From 7381b620358c2561e8690149f1d25828fdad6675 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Wed, 7 Jun 2017 19:16:22 +0200
Subject: [PATCH 03/72] MIPS: Use precise search for exit jump patching.
Contributed by Djordje Kovacevic and Stefan Pejic.
---
src/lj_asm_mips.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h
index 03270cc..d0a1ca5 100644
--- a/src/lj_asm_mips.h
+++ b/src/lj_asm_mips.h
@@ -1933,7 +1933,11 @@ void lj_asm_patchexit(jit_State *J, GCtrace *T, ExitNo exitno, MCode *target)
MCode tjump = MIPSI_J|(((uintptr_t)target>>2)&0x03ffffffu);
for (p++; p < pe; p++) {
if (*p == exitload) { /* Look for load of exit number. */
- if (((p[-1] ^ (px-p)) & 0xffffu) == 0) { /* Look for exitstub branch. */
+ /* Look for exitstub branch. Yes, this covers all used branch variants. */
+ if (((p[-1] ^ (px-p)) & 0xffffu) == 0 &&
+ ((p[-1] & 0xf0000000u) == MIPSI_BEQ ||
+ (p[-1] & 0xfc1e0000u) == MIPSI_BLTZ ||
+ (p[-1] & 0xffe00000u) == MIPSI_BC1F)) {
ptrdiff_t delta = target - p;
if (((delta + 0x8000) >> 16) == 0) { /* Patch in-range branch. */
patchbranch:
--
2.20.1