[COMMITTED][GCC9] Backport RISC-V: Fix more splitters accidentally calling gen_reg_rtx.

[Kito Cheng <kito dot cheng at gmail dot com>]

This patch fix PR target/91635, back port to gcc-9-branch from trunk,
committed :)

From 430008a798822a0b6894308c841e77a5adc920d5 Mon Sep 17 00:00:00 2001
From: kito <kito@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 20 Sep 2019 10:41:51 +0000
Subject: [PATCH] RISC-V: Fix more splitters accidentally calling gen_reg_rtx.

	PR target/91683
	* config/riscv/riscv-protos.h (riscv_split_symbol): New bool parameter.
	(riscv_move_integer): Likewise.
	* config/riscv/riscv.c (riscv_split_integer): Pass FALSE for new
	riscv_move_integer arg.
	(riscv_legitimize_move): Likewise.
	(riscv_force_temporary): New parameter in_splitter.  Don't call
	force_reg if true.
	(riscv_unspec_offset_high): Pass FALSE for new riscv_force_temporary
	arg.
	(riscv_add_offset): Likewise.
	(riscv_split_symbol): New parameter in_splitter.  Pass to
	riscv_force_temporary.
	(riscv_legitimize_address): Pass FALSE for new riscv_split_symbol
	arg.
	(riscv_move_integer): New parameter in_splitter.  New local
	can_create_psuedo.  Don't call riscv_split_integer or force_reg when
	in_splitter TRUE.
	(riscv_legitimize_const_move): Pass FALSE for new riscv_move_integer,
	riscv_split_symbol, and riscv_force_temporary args.
	* config/riscv/riscv.md (low<mode>+1): Pass TRUE for new
	riscv_move_integer arg.
	(low<mode>+2): Pass TRUE for new riscv_split_symbol arg.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-9-branch@275997 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog                   | 29 +++++++++++++++++++++
 gcc/config/riscv/riscv-protos.h |  4 +--
 gcc/config/riscv/riscv.c        | 45 ++++++++++++++++++++-------------
 gcc/config/riscv/riscv.md       |  6 ++---
 4 files changed, 62 insertions(+), 22 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1d694a7f7c9..f1f923a06dd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,32 @@
+2019-09-20  Kito Cheng  <kito.cheng@sifive.com>
+
+	Backport from mainline
+	2019-09-18  Jim Wilson  <jimw@sifive.com>
+
+	PR target/91683
+	* config/riscv/riscv-protos.h (riscv_split_symbol): New bool parameter.
+	(riscv_move_integer): Likewise.
+	* config/riscv/riscv.c (riscv_split_integer): Pass FALSE for new
+	riscv_move_integer arg.
+	(riscv_legitimize_move): Likewise.
+	(riscv_force_temporary): New parameter in_splitter.  Don't call
+	force_reg if true.
+	(riscv_unspec_offset_high): Pass FALSE for new riscv_force_temporary
+	arg.
+	(riscv_add_offset): Likewise.
+	(riscv_split_symbol): New parameter in_splitter.  Pass to
+	riscv_force_temporary.
+	(riscv_legitimize_address): Pass FALSE for new riscv_split_symbol
+	arg.
+	(riscv_move_integer): New parameter in_splitter.  New local
+	can_create_psuedo.  Don't call riscv_split_integer or force_reg when
+	in_splitter TRUE.
+	(riscv_legitimize_const_move): Pass FALSE for new riscv_move_integer,
+	riscv_split_symbol, and riscv_force_temporary args.
+	* config/riscv/riscv.md (low<mode>+1): Pass TRUE for new
+	riscv_move_integer arg.
+	(low<mode>+2): Pass TRUE for new riscv_split_symbol arg.
+
 2019-09-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR target/91269
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 8b510f87df8..5b0bbdd7cb4 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -44,10 +44,10 @@ extern int riscv_const_insns (rtx);
 extern int riscv_split_const_insns (rtx);
 extern int riscv_load_store_insns (rtx, rtx_insn *);
 extern rtx riscv_emit_move (rtx, rtx);
-extern bool riscv_split_symbol (rtx, rtx, machine_mode, rtx *);
+extern bool riscv_split_symbol (rtx, rtx, machine_mode, rtx *, bool);
 extern bool riscv_split_symbol_type (enum riscv_symbol_type);
 extern rtx riscv_unspec_address (rtx, enum riscv_symbol_type);
-extern void riscv_move_integer (rtx, rtx, HOST_WIDE_INT);
+extern void riscv_move_integer (rtx, rtx, HOST_WIDE_INT, bool);
 extern bool riscv_legitimize_move (machine_mode, rtx, rtx);
 extern rtx riscv_subword (rtx, bool);
 extern bool riscv_split_64bit_move_p (rtx, rtx);
diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
index 35219956c80..5cb295d3abb 100644
--- a/gcc/config/riscv/riscv.c
+++ b/gcc/config/riscv/riscv.c
@@ -508,8 +508,8 @@ riscv_split_integer (HOST_WIDE_INT val, machine_mode mode)
   unsigned HOST_WIDE_INT hival = sext_hwi ((val - loval) >> 32, 32);
   rtx hi = gen_reg_rtx (mode), lo = gen_reg_rtx (mode);
 
-  riscv_move_integer (hi, hi, hival);
-  riscv_move_integer (lo, lo, loval);
+  riscv_move_integer (hi, hi, hival, FALSE);
+  riscv_move_integer (lo, lo, loval, FALSE);
 
   hi = gen_rtx_fmt_ee (ASHIFT, mode, hi, GEN_INT (32));
   hi = force_reg (mode, hi);
@@ -1021,9 +1021,12 @@ riscv_force_binary (machine_mode mode, enum rtx_code code, rtx x, rtx y)
    are allowed, copy it into a new register, otherwise use DEST.  */
 
 static rtx
-riscv_force_temporary (rtx dest, rtx value)
+riscv_force_temporary (rtx dest, rtx value, bool in_splitter)
 {
-  if (can_create_pseudo_p ())
+  /* We can't call gen_reg_rtx from a splitter, because this might realloc
+     the regno_reg_rtx array, which would invalidate reg rtx pointers in the
+     combine undo buffer.  */
+  if (can_create_pseudo_p () && !in_splitter)
     return force_reg (Pmode, value);
   else
     {
@@ -1082,7 +1085,7 @@ static rtx
 riscv_unspec_offset_high (rtx temp, rtx addr, enum riscv_symbol_type symbol_type)
 {
   addr = gen_rtx_HIGH (Pmode, riscv_unspec_address (addr, symbol_type));
-  return riscv_force_temporary (temp, addr);
+  return riscv_force_temporary (temp, addr, FALSE);
 }
 
 /* Load an entry from the GOT for a TLS GD access.  */
@@ -1130,7 +1133,8 @@ static rtx riscv_tls_add_tp_le (rtx dest, rtx base, rtx sym)
    is guaranteed to be a legitimate address for mode MODE.  */
 
 bool
-riscv_split_symbol (rtx temp, rtx addr, machine_mode mode, rtx *low_out)
+riscv_split_symbol (rtx temp, rtx addr, machine_mode mode, rtx *low_out,
+		    bool in_splitter)
 {
   enum riscv_symbol_type symbol_type;
 
@@ -1146,7 +1150,7 @@ riscv_split_symbol (rtx temp, rtx addr, machine_mode mode, rtx *low_out)
       case SYMBOL_ABSOLUTE:
 	{
 	  rtx high = gen_rtx_HIGH (Pmode, copy_rtx (addr));
-	  high = riscv_force_temporary (temp, high);
+	  high = riscv_force_temporary (temp, high, in_splitter);
 	  *low_out = gen_rtx_LO_SUM (Pmode, high, addr);
 	}
 	break;
@@ -1205,8 +1209,9 @@ riscv_add_offset (rtx temp, rtx reg, HOST_WIDE_INT offset)
 	 overflow, so we need to force a sign-extension check.  */
       high = gen_int_mode (CONST_HIGH_PART (offset), Pmode);
       offset = CONST_LOW_PART (offset);
-      high = riscv_force_temporary (temp, high);
-      reg = riscv_force_temporary (temp, gen_rtx_PLUS (Pmode, high, reg));
+      high = riscv_force_temporary (temp, high, FALSE);
+      reg = riscv_force_temporary (temp, gen_rtx_PLUS (Pmode, high, reg),
+				   FALSE);
     }
   return plus_constant (Pmode, reg, offset);
 }
@@ -1315,7 +1320,7 @@ riscv_legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED,
     return riscv_legitimize_tls_address (x);
 
   /* See if the address can split into a high part and a LO_SUM.  */
-  if (riscv_split_symbol (NULL, x, mode, &addr))
+  if (riscv_split_symbol (NULL, x, mode, &addr, FALSE))
     return riscv_force_address (addr, mode);
 
   /* Handle BASE + OFFSET using riscv_add_offset.  */
@@ -1337,17 +1342,23 @@ riscv_legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED,
 /* Load VALUE into DEST.  TEMP is as for riscv_force_temporary.  */
 
 void
-riscv_move_integer (rtx temp, rtx dest, HOST_WIDE_INT value)
+riscv_move_integer (rtx temp, rtx dest, HOST_WIDE_INT value,
+		    bool in_splitter)
 {
   struct riscv_integer_op codes[RISCV_MAX_INTEGER_OPS];
   machine_mode mode;
   int i, num_ops;
   rtx x;
 
+  /* We can't call gen_reg_rtx from a splitter, because this might realloc
+     the regno_reg_rtx array, which would invalidate reg rtx pointers in the
+     combine undo buffer.  */
+  bool can_create_pseudo = can_create_pseudo_p () && ! in_splitter;
+
   mode = GET_MODE (dest);
   num_ops = riscv_build_integer (codes, value, mode);
 
-  if (can_create_pseudo_p () && num_ops > 2 /* not a simple constant */
+  if (can_create_pseudo && num_ops > 2 /* not a simple constant */
       && num_ops >= riscv_split_integer_cost (value))
     x = riscv_split_integer (value, mode);
   else
@@ -1357,7 +1368,7 @@ riscv_move_integer (rtx temp, rtx dest, HOST_WIDE_INT value)
 
       for (i = 1; i < num_ops; i++)
 	{
-	  if (!can_create_pseudo_p ())
+	  if (!can_create_pseudo)
 	    x = riscv_emit_set (temp, x);
 	  else
 	    x = force_reg (mode, x);
@@ -1381,12 +1392,12 @@ riscv_legitimize_const_move (machine_mode mode, rtx dest, rtx src)
   /* Split moves of big integers into smaller pieces.  */
   if (splittable_const_int_operand (src, mode))
     {
-      riscv_move_integer (dest, dest, INTVAL (src));
+      riscv_move_integer (dest, dest, INTVAL (src), FALSE);
       return;
     }
 
   /* Split moves of symbolic constants into high/low pairs.  */
-  if (riscv_split_symbol (dest, src, MAX_MACHINE_MODE, &src))
+  if (riscv_split_symbol (dest, src, MAX_MACHINE_MODE, &src, FALSE))
     {
       riscv_emit_set (dest, src);
       return;
@@ -1407,7 +1418,7 @@ riscv_legitimize_const_move (machine_mode mode, rtx dest, rtx src)
   if (offset != const0_rtx
       && (targetm.cannot_force_const_mem (mode, src) || can_create_pseudo_p ()))
     {
-      base = riscv_force_temporary (dest, base);
+      base = riscv_force_temporary (dest, base, FALSE);
       riscv_emit_move (dest, riscv_add_offset (NULL, base, INTVAL (offset)));
       return;
     }
@@ -1416,7 +1427,7 @@ riscv_legitimize_const_move (machine_mode mode, rtx dest, rtx src)
 
   /* When using explicit relocs, constant pool references are sometimes
      not legitimate addresses.  */
-  riscv_split_symbol (dest, XEXP (src, 0), mode, &XEXP (src, 0));
+  riscv_split_symbol (dest, XEXP (src, 0), mode, &XEXP (src, 0), FALSE);
   riscv_emit_move (dest, src);
 }
 
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 7850c41f3c7..e40535c9e40 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -1284,7 +1284,7 @@
   ""
   [(const_int 0)]
 {
-  riscv_move_integer (operands[2], operands[0], INTVAL (operands[1]));
+  riscv_move_integer (operands[2], operands[0], INTVAL (operands[1]), TRUE);
   DONE;
 })
 
@@ -1293,11 +1293,11 @@
   [(set (match_operand:P 0 "register_operand")
 	(match_operand:P 1))
    (clobber (match_operand:P 2 "register_operand"))]
-  "riscv_split_symbol (operands[2], operands[1], MAX_MACHINE_MODE, NULL)"
+  "riscv_split_symbol (operands[2], operands[1], MAX_MACHINE_MODE, NULL, TRUE)"
   [(set (match_dup 0) (match_dup 3))]
 {
   riscv_split_symbol (operands[2], operands[1],
-		     MAX_MACHINE_MODE, &operands[3]);
+		      MAX_MACHINE_MODE, &operands[3], TRUE);
 })
 
 ;; 64-bit integer moves
-- 
2.17.1