re PR rtl-optimization/93088 (Compile time hog on gcc/testsuite/gcc.target/i386/pr563...

	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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
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"