Mark XXSPLTIW/XXSPLTIDP as prefixed -- PR 104136

If you compile module_advect_em.F90 with -Ofast -mcpu=power10, one module
is large enough that we can't use a single conditional jump to span the
function.  Instead, GCC has to reverse the condition, and do a conditional
jump around an unconditional branch.  It turns out when xxspltiw and
xxspltdp instructions were generated, they were not marked as being
prefixed (i.e. length of 12 bytes instead of 4 bytes).  This meant the
calculations for the branch length were off, which in turn meant the
assembler raised an error because it couldn't do the conditional jump.

The fix is to explicitly set the prefixed attribute when we are loading up
vector constants with the xxspltiw or xxspltidp instructions.

I have removed the code that sets the prefixed attribute for xxspltiw,
xxspltidp, and xxsplti32dx instructions, since it no longer will be invoked.

I have also explicitly set the prefixed attribute for load SF and DF mode
constants with xxsplitw and xxspltidp.  Previously, it was not set on these
insns, but when the insn was split to get the XXSPLTIW/XXSPLTIDP forms, those
forms already had the prefixed attribute set.

2022-01-21  Michael Meissner  <meissner@the-meissners.org>

gcc/
	PR target/104136
	* config/rs6000/rs6000-protos.h (prefixed_xxsplti_p): Delete.
	* config/rs6000/rs6000.cc (prefixed_xxsplti_p): Delete.
	* config/rs6000/rs6000.md (prefixed attribute): Delete section
	that sets the prefixed attribute for xxspltiw, xxspltidp, and
	xxsplti32dx instructions.
	(movsf_hardfloat): Explicitly set the prefixed attribute
	when xxspltiw and xxspltidp instructions are generated.
	(mov<mode>_hardfloat32): Likewise.
	(mov<mode>_hardfloat64): Likewise.
	* config/rs6000/vsx.md (vsx_mov<mode>_64bit): Explicitly set the
	prefixed attribute for xxspltiw and xxspltidp instructions.
	(vsx_mov<mode>_32bit): Likewise.

4 files changed, 27 insertions, 48 deletions

diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h
index e322ac0..3ea0102 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -199,7 +199,6 @@ enum non_prefixed_form reg_to_non_prefixed (rtx reg, machine_mode mode);
 extern bool prefixed_load_p (rtx_insn *);
 extern bool prefixed_store_p (rtx_insn *);
 extern bool prefixed_paddi_p (rtx_insn *);
-extern bool prefixed_xxsplti_p (rtx_insn *);
 extern void rs6000_asm_output_opcode (FILE *);
 extern void output_pcrel_opt_reloc (rtx);
 extern void rs6000_final_prescan_insn (rtx_insn *, rtx [], int);
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 587fb11..943f53e 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -26609,44 +26609,6 @@ prefixed_paddi_p (rtx_insn *insn)
   return (iform == INSN_FORM_PCREL_EXTERNAL || iform == INSN_FORM_PCREL_LOCAL);
 }
 
-/* Whether an instruction is a prefixed XXSPLTI* instruction.  This is called
-   from the prefixed attribute processing.  */
-
-bool
-prefixed_xxsplti_p (rtx_insn *insn)
-{
-  rtx set = single_set (insn);
-  if (!set)
-    return false;
-
-  rtx dest = SET_DEST (set);
-  rtx src = SET_SRC (set);
-  machine_mode mode = GET_MODE (dest);
-
-  if (!REG_P (dest) && !SUBREG_P (dest))
-    return false;
-
-  if (GET_CODE (src) == UNSPEC)
-    {
-      int unspec = XINT (src, 1);
-      return (unspec == UNSPEC_XXSPLTIW
-	      || unspec == UNSPEC_XXSPLTIDP
-	      || unspec == UNSPEC_XXSPLTI32DX);
-    }
-
-  vec_const_128bit_type vsx_const;
-  if (vec_const_128bit_to_bytes (src, mode, &vsx_const))
-    {
-      if (constant_generates_xxspltiw (&vsx_const))
-	return true;
-
-      if (constant_generates_xxspltidp (&vsx_const))
-	return true;
-    }
-
-  return false;
-}
-
 /* Whether the next instruction needs a 'p' prefix issued before the
    instruction is printed out.  */
 static bool prepend_p_to_next_insn;
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 59531b6..4e22118 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -315,11 +315,6 @@
 	 (eq_attr "type" "integer,add")
 	 (if_then_else (match_test "prefixed_paddi_p (insn)")
 		       (const_string "yes")
-		       (const_string "no"))
-
-	 (eq_attr "type" "vecperm")
-	 (if_then_else (match_test "prefixed_xxsplti_p (insn)")
-		       (const_string "yes")
 		       (const_string "no"))]
 
 	(const_string "no")))
@@ -7857,7 +7852,11 @@
    (set_attr "isa"
 	"*,          *,         p9v,        p8v,       *,         p9v,
 	 p8v,        *,         *,          *,         *,         *,
-	 *,          *,         *,          *,         p10")])
+	 *,          *,         *,          *,         p10")
+   (set_attr "prefixed"
+	"*,          *,         *,          *,         *,         *,
+	 *,          *,         *,          *,         *,         *,
+	 *,          *,         *,          *,         yes")])
 
 ;;	LWZ          LFIWZX     STW        STFIWX     MTVSRWZ    MFVSRWZ
 ;;	FMR          MR         MT%0       MF%1       NOP
@@ -8159,7 +8158,11 @@
    (set_attr "isa"
             "*,           *,          *,          p9v,        p9v,
              p7v,         p7v,        *,          *,          *,
-             *,           *,          *,          p10")])
+             *,           *,          *,          p10")
+   (set_attr "prefixed"
+            "*,           *,          *,          *,          *,
+             *,           *,          *,          *,          *,
+             *,           *,          *,          yes")])
 
 ;;           STW      LWZ     MR      G-const H-const F-const
 
@@ -8232,7 +8235,12 @@
             "*,           *,          *,          p9v,        p9v,
              p7v,         p7v,        *,          *,          *,
              *,           *,          *,          *,          *,
-             *,           p8v,        p8v,        p10")])
+             *,           p8v,        p8v,        p10")
+   (set_attr "prefixed"
+            "*,           *,          *,          *,          *,
+             *,           *,          *,          *,          *,
+             *,           *,          *,          *,          *,
+             *,           *,          *,          *")])
 
 ;;           STD      LD       MR      MT<SPR> MF<SPR> G-const
 ;;           H-const  F-const  Special
diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index e84ffb6..c8c891e 100644
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -1237,7 +1237,12 @@
                "<VSisa>,   <VSisa>,   <VSisa>,   *,         *,         *,
                 *,         *,         *,         *,         p9v,       *,
                 p10,       p10,
-                <VSisa>,   *,         *,         *,         *")])
+                <VSisa>,   *,         *,         *,         *")
+   (set_attr "prefixed"
+               "*,         *,         *,         *,         *,         *,
+                *,         *,         *,         *,         *,         *,
+                *,         yes,
+                *,         *,         *,         *,         *")])
 
 ;;              VSX store  VSX load   VSX move   GPR load   GPR store  GPR move
 ;;              LXVKQ      XXSPLTI*
@@ -1276,6 +1281,11 @@
                "<VSisa>,   <VSisa>,   <VSisa>,   *,         *,         *,
                 p10,       p10,
                 p9v,       *,         <VSisa>,   *,         *,
+                *,         *")
+   (set_attr "prefixed"
+               "*,         *,         *,         *,         *,         *,
+                *,         yes,
+                *,         *,         *,         *,         *,
                 *,         *")])
 
 ;; Explicit  load/store expanders for the builtin functions