re PR rtl-optimization/83723 (ICE: in gen_rtx_SUBREG, at emit-rtl.c:1010)

	PR rtl-optimization/83723
	* lra-int.h (lra_substitute_pseudo): Add DEBUG_P argument.
	* lra.c (lra_substitute_pseudo): Likewise.  If true, use
	gen_rtx_raw_SUBREG instead of gen_rtx_SUBREG.  Pass DEBUG_P to
	recursive calls.
	(lra_substitute_pseudo_within_insn): Adjust lra_substitute_pseudo
	callers.
	* lra-constraints.c (inherit_reload_reg, split_reg): Likewise.

	* gcc.dg/pr83723.c: New test.

From-SVN: r257725

gcc/ChangeLog

+2018-02-16  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/83723
+	* lra-int.h (lra_substitute_pseudo): Add DEBUG_P argument.
+	* lra.c (lra_substitute_pseudo): Likewise.  If true, use
+	gen_rtx_raw_SUBREG instead of gen_rtx_SUBREG.  Pass DEBUG_P to
+	recursive calls.
+	(lra_substitute_pseudo_within_insn): Adjust lra_substitute_pseudo
+	callers.
+	* lra-constraints.c (inherit_reload_reg, split_reg): Likewise.
+
 2018-02-16  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/81443

gcc/lra-constraints.c

@@ -5287,7 +5287,8 @@ inherit_reload_reg (bool def_p, int original_regno,
 	  lra_assert (DEBUG_INSN_P (usage_insn));
 	  next_usage_insns = XEXP (next_usage_insns, 1);
 	}
-      lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false);
+      lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false,
+			     DEBUG_INSN_P (usage_insn));
       lra_update_insn_regno_info (as_a <rtx_insn *> (usage_insn));
       if (lra_dump_file != NULL)
 	{
@@ -5608,7 +5609,8 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
       usage_insn = XEXP (next_usage_insns, 0);
       lra_assert (DEBUG_INSN_P (usage_insn));
       next_usage_insns = XEXP (next_usage_insns, 1);
-      lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false);
+      lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false,
+			     true);
       lra_update_insn_regno_info (as_a <rtx_insn *> (usage_insn));
       if (lra_dump_file != NULL)
 	{

gcc/lra-int.h

@@ -309,7 +309,7 @@ extern void lra_update_dups (lra_insn_recog_data_t, signed char *);
 extern void lra_process_new_insns (rtx_insn *, rtx_insn *, rtx_insn *,
 				   const char *);
 
-extern bool lra_substitute_pseudo (rtx *, int, rtx, bool);
+extern bool lra_substitute_pseudo (rtx *, int, rtx, bool, bool);
 extern bool lra_substitute_pseudo_within_insn (rtx_insn *, int, rtx, bool);
 
 extern lra_insn_recog_data_t lra_set_insn_recog_data (rtx_insn *);

gcc/lra.c

@@ -1893,9 +1893,11 @@ lra_process_new_insns (rtx_insn *insn, rtx_insn *before, rtx_insn *after,
 
 /* Replace all references to register OLD_REGNO in *LOC with pseudo
    register NEW_REG.  Try to simplify subreg of constant if SUBREG_P.
-   Return true if any change was made.  */
+   DEBUG_P is if LOC is within a DEBUG_INSN.  Return true if any
+   change was made.  */
 bool
-lra_substitute_pseudo (rtx *loc, int old_regno, rtx new_reg, bool subreg_p)
+lra_substitute_pseudo (rtx *loc, int old_regno, rtx new_reg, bool subreg_p,
+		       bool debug_p)
 {
   rtx x = *loc;
   bool result = false;
@@ -1931,11 +1933,14 @@ lra_substitute_pseudo (rtx *loc, int old_regno, rtx new_reg, bool subreg_p)
       if (mode != inner_mode
 	  && ! (CONST_INT_P (new_reg) && SCALAR_INT_MODE_P (mode)))
 	{
-	  if (!partial_subreg_p (mode, inner_mode)
-	      || ! SCALAR_INT_MODE_P (inner_mode))
-	    new_reg = gen_rtx_SUBREG (mode, new_reg, 0);
+	  poly_uint64 offset = 0;
+	  if (partial_subreg_p (mode, inner_mode)
+	      && SCALAR_INT_MODE_P (inner_mode))
+	    offset = subreg_lowpart_offset (mode, inner_mode);
+	  if (debug_p)
+	    new_reg = gen_rtx_raw_SUBREG (mode, new_reg, offset);
 	  else
-	    new_reg = gen_lowpart_SUBREG (mode, new_reg);
+	    new_reg = gen_rtx_SUBREG (mode, new_reg, offset);
 	}
       *loc = new_reg;
       return true;
@@ -1948,14 +1953,14 @@ lra_substitute_pseudo (rtx *loc, int old_regno, rtx new_reg, bool subreg_p)
       if (fmt[i] == 'e')
 	{
 	  if (lra_substitute_pseudo (&XEXP (x, i), old_regno,
-				     new_reg, subreg_p))
+				     new_reg, subreg_p, debug_p))
 	    result = true;
 	}
       else if (fmt[i] == 'E')
 	{
 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
 	    if (lra_substitute_pseudo (&XVECEXP (x, i, j), old_regno,
-				       new_reg, subreg_p))
+				       new_reg, subreg_p, debug_p))
 	      result = true;
 	}
     }
@@ -1970,7 +1975,8 @@ lra_substitute_pseudo_within_insn (rtx_insn *insn, int old_regno,
 				   rtx new_reg, bool subreg_p)
 {
   rtx loc = insn;
-  return lra_substitute_pseudo (&loc, old_regno, new_reg, subreg_p);
+  return lra_substitute_pseudo (&loc, old_regno, new_reg, subreg_p,
+				DEBUG_INSN_P (insn));
 }
 
 

gcc/testsuite/ChangeLog

+2018-02-16  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/83723
+	* gcc.dg/pr83723.c: New test.
+
 2018-02-16  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/84399

gcc/testsuite/gcc.dg/pr83723.c

+/* PR rtl-optimization/83723 */
+/* { dg-do compile } */
+/* { dg-options "-g -O2" } */
+/* { dg-additional-options "-mfpmath=sse -msse2" { target i?86-*-* x86_64-*-* } } */
+/* { dg-additional-options "-fpie" { target pie } } */
+
+int foo (void);
+float bar (float);
+int *v;
+
+void
+baz (void)
+{
+  float a = bar (0.0);
+  bar (a);
+  if (v)
+    bar (1.0);
+  if (a < 1.0)
+    a = foo () / a;
+}