From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 26 Jun 2018 11:35:52 +0000 (+0200)
Subject: re PR target/86314 (GCC 7.x and 8.x zero out "eax" before using "rax" in "lock bts")
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d37a91e5c57c518c91de2e570fdbf9d96f90dd41;p=gcc.git

re PR target/86314 (GCC 7.x and 8.x zero out "eax" before using "rax" in "lock bts")

	PR target/86314
	* config/i386/i386.md (setcc + movzbl to xor + setcc peephole2s):
	Check reg_overlap_mentioned_p in addition to reg_set_p with the same
	operands.

	* gcc.dg/pr86314.c: New test.

From-SVN: r262141
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ec68212bc0a..13b648cab29 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-06-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/86314
+	* config/i386/i386.md (setcc + movzbl to xor + setcc peephole2s):
+	Check reg_overlap_mentioned_p in addition to reg_set_p with the same
+	operands.
+
 2018-06-26  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/86287
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 6f2300057aa..559ad9334a7 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -12761,6 +12761,7 @@
   "(peep2_reg_dead_p (3, operands[1])
     || operands_match_p (operands[1], operands[3]))
    && ! reg_overlap_mentioned_p (operands[3], operands[0])
+   && ! reg_overlap_mentioned_p (operands[3], operands[4])
    && ! reg_set_p (operands[3], operands[4])
    && peep2_regno_dead_p (0, FLAGS_REG)"
   [(parallel [(set (match_dup 5) (match_dup 0))
@@ -12786,6 +12787,7 @@
     || operands_match_p (operands[2], operands[4]))
    && ! reg_overlap_mentioned_p (operands[4], operands[0])
    && ! reg_overlap_mentioned_p (operands[4], operands[1])
+   && ! reg_overlap_mentioned_p (operands[4], operands[5])
    && ! reg_set_p (operands[4], operands[5])
    && refers_to_regno_p (FLAGS_REG, operands[1], (rtx *)NULL)
    && peep2_regno_dead_p (0, FLAGS_REG)"
@@ -12835,6 +12837,7 @@
   "(peep2_reg_dead_p (3, operands[1])
     || operands_match_p (operands[1], operands[3]))
    && ! reg_overlap_mentioned_p (operands[3], operands[0])
+   && ! reg_overlap_mentioned_p (operands[3], operands[4])
    && ! reg_set_p (operands[3], operands[4])
    && peep2_regno_dead_p (0, FLAGS_REG)"
   [(parallel [(set (match_dup 5) (match_dup 0))
@@ -12861,6 +12864,7 @@
     || operands_match_p (operands[2], operands[4]))
    && ! reg_overlap_mentioned_p (operands[4], operands[0])
    && ! reg_overlap_mentioned_p (operands[4], operands[1])
+   && ! reg_overlap_mentioned_p (operands[4], operands[5])
    && ! reg_set_p (operands[4], operands[5])
    && refers_to_regno_p (FLAGS_REG, operands[1], (rtx *)NULL)
    && peep2_regno_dead_p (0, FLAGS_REG)"
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7aea7efb21f..3931bfe8525 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2018-06-26  Jakub Jelinek  <jakub@redhat.com>
 
+	PR target/86314
+	* gcc.dg/pr86314.c: New test.
+
 	PR debug/86257
 	* gcc.target/i386/pr86257.c: Add -mtls-dialect=gnu to dg-options.
 
diff --git a/gcc/testsuite/gcc.dg/pr86314.c b/gcc/testsuite/gcc.dg/pr86314.c
new file mode 100644
index 00000000000..8962a3cf2ff
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr86314.c
@@ -0,0 +1,20 @@
+// PR target/86314
+// { dg-do run { target sync_int_long } }
+// { dg-options "-O2" }
+
+__attribute__((noinline, noclone)) unsigned long
+foo (unsigned long *p)
+{
+  unsigned long m = 1UL << ((*p & 1) ? 1 : 0);
+  unsigned long n = __atomic_fetch_or (p, m, __ATOMIC_SEQ_CST);
+  return (n & m) == 0;
+}
+
+int
+main ()
+{
+  unsigned long v = 1;
+  if (foo (&v) != 1)
+    __builtin_abort ();
+  return 0;
+}