[gcc r12-6047] rs6000: Redo darn (PR103624)

[gcc r12-6047] rs6000: Redo darn (PR103624)

[Segher Boessenkool]

https://gcc.gnu.org/g:7194397966e6a007cee42360f96834377c3121a4

commit r12-6047-g7194397966e6a007cee42360f96834377c3121a4
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date:   Fri Dec 17 16:59:55 2021 +0000

    rs6000: Redo darn (PR103624)
    
    The builtins now all return "long".  The patterns have :GPR as the
    output mode, so they can be 32-bit as well (the instruction makes sense
    in 32 bit just fine).  The builtins expand to the DImode version
    normally, but to the SImode if {32bit} is true.
    
    2021-12-17  Segher Boessenkool <segher@kernel.crashing.org>
    
            PR target/103624
            * config/rs6000/rs6000-builtins.def (__builtin_darn): Expand to
            darn_64_di.  Add {32bit} attribute.  Return long.
            (__builtin_darn_32): Expand to darn_32_di.  Add {32bit} attribute.
            Return long.
            (__builtin_darn_raw): Expand to darn_raw_di.  Add {32bit} attribute.
            Return long.
            * config/rs6000/rs6000-call.c (rs6000_expand_builtin): Expand the darn
            builtins to the _si variants for -m32.
            * config/rs6000/rs6000.md (UNSPECV_DARN_32, UNSPECV_DARN_RAW): Delete.
            (UNSPECV_DARN): Update comment.
            (darn_32, darn_raw, darn): Delete.
            (darn_32_<mode>, darn_64_<mode>, darn_raw_<mode> for GPR): New.
            (@darn<mode> for GPR): New.

Diff:
---
 gcc/config/rs6000/rs6000-builtins.def | 12 ++++-----
 gcc/config/rs6000/rs6000-call.c       |  6 +++++
 gcc/config/rs6000/rs6000.md           | 47 +++++++++++++++++++++--------------
 3 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/gcc/config/rs6000/rs6000-builtins.def b/gcc/config/rs6000/rs6000-builtins.def
index 45ce160bd42..3ad5a135eae 100644
--- a/gcc/config/rs6000/rs6000-builtins.def
+++ b/gcc/config/rs6000/rs6000-builtins.def
@@ -2798,14 +2798,14 @@
 
 ; Miscellaneous P9 functions
 [power9]
-  signed long long __builtin_darn ();
-    DARN darn {}
+  signed long __builtin_darn ();
+    DARN darn_64_di {32bit}
 
-  signed int __builtin_darn_32 ();
-    DARN_32 darn_32 {}
+  signed long __builtin_darn_32 ();
+    DARN_32 darn_32_di {32bit}
 
-  signed long long __builtin_darn_raw ();
-    DARN_RAW darn_raw {}
+  signed long __builtin_darn_raw ();
+    DARN_RAW darn_raw_di {32bit}
 
   const signed int __builtin_dtstsfi_eq_dd (const int<6>, _Decimal64);
     TSTSFI_EQ_DD dfptstsfi_eq_dd {}
diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index b98f4a4c97f..cc55174c6b7 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -5631,6 +5631,12 @@ rs6000_expand_builtin (tree exp, rtx target, rtx /* subtarget */,
 	icode = CODE_FOR_rs6000_mftb_si;
       else if (fcode == RS6000_BIF_BPERMD)
 	icode = CODE_FOR_bpermd_si;
+      else if (fcode == RS6000_BIF_DARN)
+	icode = CODE_FOR_darn_64_si;
+      else if (fcode == RS6000_BIF_DARN_32)
+	icode = CODE_FOR_darn_32_si;
+      else if (fcode == RS6000_BIF_DARN_RAW)
+	icode = CODE_FOR_darn_raw_si;
       else
 	gcc_unreachable ();
     }
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 4122acb98cf..9be484c7cf8 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -172,9 +172,7 @@
    UNSPECV_EH_RR		; eh_reg_restore
    UNSPECV_ISYNC		; isync instruction
    UNSPECV_MFTB			; move from time base
-   UNSPECV_DARN			; darn 1 (deliver a random number)
-   UNSPECV_DARN_32		; darn 2
-   UNSPECV_DARN_RAW		; darn 0
+   UNSPECV_DARN			; darn (deliver a random number)
    UNSPECV_NLGR			; non-local goto receiver
    UNSPECV_MFFS			; Move from FPSCR
    UNSPECV_MFFSL		; Move from FPSCR light instruction version
@@ -15065,25 +15063,36 @@
 \f
 ;; Miscellaneous ISA 3.0 (power9) instructions
 
-(define_insn "darn_32"
-  [(set (match_operand:SI 0 "register_operand" "=r")
-        (unspec_volatile:SI [(const_int 0)] UNSPECV_DARN_32))]
+(define_expand "darn_32_<mode>"
+  [(use (match_operand:GPR 0 "register_operand"))]
   "TARGET_P9_MISC"
-  "darn %0,0"
-  [(set_attr "type" "integer")])
+{
+  emit_insn (gen_darn (<MODE>mode, operands[0], const0_rtx));
+  DONE;
+})
 
-(define_insn "darn_raw"
-  [(set (match_operand:DI 0 "register_operand" "=r")
-        (unspec_volatile:DI [(const_int 0)] UNSPECV_DARN_RAW))]
-  "TARGET_P9_MISC && TARGET_64BIT"
-  "darn %0,2"
-  [(set_attr "type" "integer")])
+(define_expand "darn_64_<mode>"
+  [(use (match_operand:GPR 0 "register_operand"))]
+  "TARGET_P9_MISC"
+{
+  emit_insn (gen_darn (<MODE>mode, operands[0], const1_rtx));
+  DONE;
+})
 
-(define_insn "darn"
-  [(set (match_operand:DI 0 "register_operand" "=r")
-        (unspec_volatile:DI [(const_int 0)] UNSPECV_DARN))]
-  "TARGET_P9_MISC && TARGET_64BIT"
-  "darn %0,1"
+(define_expand "darn_raw_<mode>"
+  [(use (match_operand:GPR 0 "register_operand"))]
+  "TARGET_P9_MISC"
+{
+  emit_insn (gen_darn (<MODE>mode, operands[0], const2_rtx));
+  DONE;
+})
+
+(define_insn "@darn<mode>"
+  [(set (match_operand:GPR 0 "register_operand" "=r")
+        (unspec_volatile:GPR [(match_operand 1 "const_int_operand" "n")]
+			     UNSPECV_DARN))]
+  "TARGET_P9_MISC"
+  "darn %0,%1"
   [(set_attr "type" "integer")])
 
 ;; Test byte within range.