From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 3 Jan 2020 09:10:13 +0000 (+0100)
Subject: re PR rtl-optimization/93088 (Compile time hog on gcc/testsuite/gcc.target/i386/pr563... 
X-Git-Tag: upstream/12.2.0~19309
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5a6e28b5bae7a236b35994d0f64fd902a574872c;p=platform%2Fupstream%2Fgcc.git

re PR rtl-optimization/93088 (Compile time hog on gcc/testsuite/gcc.target/i386/pr56348.c w/ -O3 -funroll-loops -fno-tree-dominator-opts -fno-tree-vrp)

	PR rtl-optimization/93088
	* loop-iv.c (find_single_def_src): Punt after looking through
	128 reg copies for regs with single definitions.  Move definitions
	to first uses.

	* gcc.target/i386/pr93088.c: New test.

From-SVN: r279854
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c7883ed..ce5cb00 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-01-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/93088
+	* loop-iv.c (find_single_def_src): Punt after looking through
+	128 reg copies for regs with single definitions.  Move definitions
+	to first uses.
+
 2020-01-02  Dennis Zhang  <dennis.zhang@arm.com>
 
 	* config/arm/arm-c.c (arm_cpu_builtins): Define
diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c
index 83c3eef..6a59954 100644
--- a/gcc/loop-iv.c
+++ b/gcc/loop-iv.c
@@ -1384,24 +1384,23 @@ simple_rhs_p (rtx rhs)
 static rtx
 find_single_def_src (unsigned int regno)
 {
-  df_ref adef;
-  rtx set, src;
+  rtx src = NULL_RTX;
 
-  for (;;)
+  /* Don't look through unbounded number of single definition REG copies,
+     there might be loops for sources with uninitialized variables.  */
+  for (int cnt = 0; cnt < 128; cnt++)
     {
-      rtx note;
-      adef = DF_REG_DEF_CHAIN (regno);
+      df_ref adef = DF_REG_DEF_CHAIN (regno);
       if (adef == NULL || DF_REF_NEXT_REG (adef) != NULL
 	  || DF_REF_IS_ARTIFICIAL (adef))
 	return NULL_RTX;
 
-      set = single_set (DF_REF_INSN (adef));
+      rtx set = single_set (DF_REF_INSN (adef));
       if (set == NULL || !REG_P (SET_DEST (set))
 	  || REGNO (SET_DEST (set)) != regno)
 	return NULL_RTX;
 
-      note = find_reg_equal_equiv_note (DF_REF_INSN (adef));
-
+      rtx note = find_reg_equal_equiv_note (DF_REF_INSN (adef));
       if (note && function_invariant_p (XEXP (note, 0)))
 	{
 	  src = XEXP (note, 0);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2a3a45e..7be1d90 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/93088
+	* gcc.target/i386/pr93088.c: New test.
+
 2020-01-03  Tobias Burnus  <tobias@codesourcery.com>
 
 	PR fortran/92994
diff --git a/gcc/testsuite/gcc.target/i386/pr93088.c b/gcc/testsuite/gcc.target/i386/pr93088.c
new file mode 100644
index 0000000..dc986cf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr93088.c
@@ -0,0 +1,5 @@
+/* PR rtl-optimization/93088 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -funroll-loops -fno-tree-dominator-opts -fno-tree-vrp -w" } */
+
+#include "pr56348.c"