From: Dmitry Stogov <dmitry@zend.com>
Date: Fri, 24 Apr 2020 13:14:58 +0000 (+0300)
Subject: Skip life range with LOAD and single use
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8a04d39d1cd11b002f02c8dea6498740949fb0cd;p=php

Skip life range with LOAD and single use
---

diff --git a/ext/opcache/jit/zend_jit_trace.c b/ext/opcache/jit/zend_jit_trace.c
index 4a687dd4c9..bbebebed12 100644
--- a/ext/opcache/jit/zend_jit_trace.c
+++ b/ext/opcache/jit/zend_jit_trace.c
@@ -2094,6 +2094,12 @@ static zend_lifetime_interval** zend_jit_trace_allocate_registers(zend_jit_trace
 	for (i = 0; i < ssa->vars_count; i++) {
 		if (start[i] >= 0 && end[i] >= 0) {
 			ZEND_ASSERT(j < count);
+			if ((flags[i] & ZREG_LOAD) &&
+			    (flags[i] & ZREG_LAST_USE) &&
+			    end[i] == ssa->vars[i].use_chain) {
+				/* skip life range with single use */
+				continue;
+			}
 			intervals[i] = &list[j];
 			list[j].ssa_var = i;
 			list[j].reg = ZREG_NONE;