RISC-V: Fix more splitters accidentally calling gen_reg_rtx.
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Message ID 20190919012024.31047-1-jimw@sifive.com
State New
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  • RISC-V: Fix more splitters accidentally calling gen_reg_rtx.
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Commit Message

Jim Wilson Sept. 19, 2019, 1:20 a.m. UTC
Similar to a previous patch, adding a in_splitter arg to every function that
can be called from a define_split, so we can prevent calls to gen_reg_rtx
during combine, which can cause crashes.

Tested with riscv32-elf and riscv64-linux builds and checks with no
regressions.

Commmitted.

Jim

	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.
---
 gcc/config/riscv/riscv-protos.h |  4 +--
 gcc/config/riscv/riscv.c        | 46 ++++++++++++++++++++-------------
 gcc/config/riscv/riscv.md       |  6 ++---
 3 files changed, 33 insertions(+), 23 deletions(-)

Patch
diff mbox series

diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 69e39f7a208..5092294803c 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, machine_mode);
+extern void riscv_move_integer (rtx, rtx, HOST_WIDE_INT, machine_mode, 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 39bf87abf1c..b8a8778b92c 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, mode);
-  riscv_move_integer (lo, lo, loval, mode);
+  riscv_move_integer (hi, hi, hival, mode, FALSE);
+  riscv_move_integer (lo, lo, loval, mode, 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.  */
@@ -1339,19 +1344,24 @@  riscv_legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED,
 
 void
 riscv_move_integer (rtx temp, rtx dest, HOST_WIDE_INT value,
-		    machine_mode orig_mode)
+		    machine_mode orig_mode, 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);
   /* We use the original mode for the riscv_build_integer call, because HImode
      values are given special treatment.  */
   num_ops = riscv_build_integer (codes, value, orig_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
@@ -1361,7 +1371,7 @@  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);
@@ -1385,12 +1395,12 @@  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), mode);
+      riscv_move_integer (dest, dest, INTVAL (src), mode, 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;
@@ -1411,7 +1421,7 @@  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;
     }
@@ -1420,7 +1430,7 @@  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);
 }
 
@@ -1446,7 +1456,7 @@  riscv_legitimize_move (machine_mode mode, rtx dest, rtx src)
 	  if (splittable_const_int_operand (src, mode))
 	    {
 	      reg = gen_reg_rtx (promoted_mode);
-	      riscv_move_integer (reg, reg, INTVAL (src), mode);
+	      riscv_move_integer (reg, reg, INTVAL (src), mode, FALSE);
 	    }
 	  else
 	    reg = force_reg (promoted_mode, src);
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 744a027a1b7..d3c8f659748 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -1285,7 +1285,7 @@ 
   [(const_int 0)]
 {
   riscv_move_integer (operands[2], operands[0], INTVAL (operands[1]),
-		      <GPR:MODE>mode);
+		      <GPR:MODE>mode, TRUE);
   DONE;
 })
 
@@ -1294,11 +1294,11 @@ 
   [(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