[gcc(refs/users/meissner/heads/work089)] Add zero_extendditi2. Improve lxvr*x code generation.

[gcc(refs/users/meissner/heads/work089)] Add zero_extendditi2. Improve lxvr*x code generation.

[Michael Meissner]

https://gcc.gnu.org/g:759be8f49b16e1b3c5dece0997cc1f72fac5fc48

commit 759be8f49b16e1b3c5dece0997cc1f72fac5fc48
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu May 12 18:38:11 2022 -0400

    Add zero_extendditi2.  Improve lxvr*x code generation.
    
    This pattern adds zero_extendditi2 so that if we are extending DImode to
    TImode, and we want the result in a vector register, the compiler can
    generate MTVSRDDD.
    
    In addition the patterns for generating lxvr{b,h,w,d}x were tuned to allow
    loading to gpr registers.  This prevents needlessly doing direct moves to
    get the value into the vector registers if the gpr register was already
    selected.
    
    In updating the insn counts for two tests due to these changes, I noticed
    the tests were done at -O0.  I changed this so that the tests are now done
    at the normal -O2 optimization level.
    
    2022-05-012   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
            * config/rs6000/vsx.md (vsx_lxvr<wd>x): Add support for loading to
            GPR registers.
            (vsx_stxvr<wd>x): Add support for storing from GPR registers.
            (zero_extendditi2): New insn.
    
    gcc/testsuite/
            * gcc.target/powerpc/vsx-load-element-extend-int.c: Use -O2
            instead of -O0 and update insn counts.
            * gcc.target/powerpc/vsx-load-element-extend-short.c: Likewise.
            * gcc.target/powerpc/zero-extend-di-ti.c: New test.

Diff:
---
 gcc/config/rs6000/vsx.md                           | 82 +++++++++++++++++++---
 .../powerpc/vsx-load-element-extend-int.c          | 36 ++++------
 .../powerpc/vsx-load-element-extend-short.c        | 35 ++++-----
 .../gcc.target/powerpc/zero-extend-di-ti.c         | 62 ++++++++++++++++
 4 files changed, 164 insertions(+), 51 deletions(-)

diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index c091e5e2f47..ad971e3a1de 100644
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -1315,14 +1315,32 @@
     }
 })
 
-;; Load rightmost element from load_data
-;; using lxvrbx, lxvrhx, lxvrwx, lxvrdx.
-(define_insn "vsx_lxvr<wd>x"
-  [(set (match_operand:TI 0 "vsx_register_operand" "=wa")
-	(zero_extend:TI (match_operand:INT_ISA3  1 "memory_operand" "Z")))]
-  "TARGET_POWER10"
-  "lxvr<wd>x %x0,%y1"
-  [(set_attr "type" "vecload")])
+;; Load rightmost element from load_data using lxvrbx, lxvrhx, lxvrwx, lxvrdx.
+;; Support TImode being in a GPR register to prevent generating lvxr{d,w,b}x
+;; and then two direct moves if we ultimately need the value in a GPR register.
+(define_insn_and_split "vsx_lxvr<wd>x"
+  [(set (match_operand:TI 0 "register_operand" "=r,wa")
+	(zero_extend:TI (match_operand:INT_ISA3  1 "memory_operand" "m,Z")))]
+  "TARGET_POWERPC64 && TARGET_POWER10"
+  "@
+   #
+   lxvr<wd>x %x0,%y1"
+  "&& reload_completed && int_reg_operand (operands[0], TImode)"
+  [(set (match_dup 2) (match_dup 3))
+   (set (match_dup 4) (const_int 0))]
+{
+  rtx op0 = operands[0];
+  rtx op1 = operands[1];
+
+  operands[2] = gen_lowpart (DImode, op0);
+  operands[3] = (<MODE>mode == DImode
+		 ? op1
+		 : gen_rtx_ZERO_EXTEND (DImode, op1));
+
+  operands[4] = gen_highpart (DImode, op0);
+}
+  [(set_attr "type" "load,vecload")
+   (set_attr "num_insns" "2,*")])
 
 ;; Store rightmost element into store_data
 ;; using stxvrbx, stxvrhx, strvxwx, strvxdx.
@@ -5019,6 +5037,54 @@
   DONE;
 })
 
+;; Zero extend DI to TI.  If we don't have the MTVSRDD instruction (and LXVRDX
+;; in the case of power10), we use the machine independent code.  If we are
+;; loading up GPRs, we fall back to the old code.
+(define_insn_and_split "zero_extendditi2"
+  [(set (match_operand:TI 0 "register_operand"                 "=r,r, wa,&wa")
+	(zero_extend:TI (match_operand:DI 1 "register_operand"  "r,wa,r,  wa")))]
+  "TARGET_POWERPC64 && TARGET_P9_VECTOR"
+  "@
+   #
+   #
+   mtvsrdd %x0,0,%1
+   #"
+  "&& reload_completed
+   && (int_reg_operand (operands[0], TImode)
+       || vsx_register_operand (operands[1], DImode))"
+  [(pc)]
+{
+  rtx dest = operands[0];
+  rtx src = operands[1];
+  int dest_regno = reg_or_subregno (dest);
+
+  /* Handle conversion to GPR registers.  Load up the low part and then do
+     zero out the upper part.  */
+  if (INT_REGNO_P (dest_regno))
+    {
+      rtx dest_hi = gen_highpart (DImode, dest);
+      rtx dest_lo = gen_lowpart (DImode, dest);
+
+      emit_move_insn (dest_lo, src);
+      emit_move_insn (dest_hi, const0_rtx);
+      DONE;
+    }
+
+  /* For settomg a VSX register from another VSX register, clear the result
+     register, and use XXPERMDI to shift the value into the lower 64-bits.  */
+  rtx dest_v2di = gen_rtx_REG (V2DImode, dest_regno);
+  rtx dest_di = gen_rtx_REG (DImode, dest_regno);
+
+  emit_move_insn (dest_v2di, CONST0_RTX (V2DImode));
+  if (BYTES_BIG_ENDIAN)
+    emit_insn (gen_vsx_concat_v2di (dest_v2di, dest_di, src));
+  else
+    emit_insn (gen_vsx_concat_v2di (dest_v2di, src, dest_di));
+  DONE;
+}
+  [(set_attr "type"   "integer,mfvsr,vecmove,vecperm")
+   (set_attr "length" "8,      8,    *,      8")])
+
 ;; Sign extend DI to TI.  We provide both GPR targets and Altivec targets on
 ;; power10.  On earlier systems, the machine independent code will generate a
 ;; shift left to sign extend the 64-bit value to 128-bit.
diff --git a/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-int.c b/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-int.c
index c40e1a3a0f7..1f1281d6b75 100644
--- a/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-int.c
+++ b/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-int.c
@@ -6,33 +6,25 @@
 /* { dg-do compile { target { ! power10_hw } } } */
 /* { dg-require-effective-target power10_ok } */
 /* { dg-require-effective-target int128 } */
-
-/* Deliberately set optization to zero for this test to confirm
-   the lxvr*x instruction is generated. At higher optimization levels
-   the instruction we are looking for is sometimes replaced by other
-   load instructions. */
-/* { dg-options "-mdejagnu-cpu=power10 -O0 -save-temps" } */
-
+/* { dg-options "-mdejagnu-cpu=power10 -O2 -save-temps" } */
 /* { dg-final { scan-assembler-times {\mlxvrwx\M} 2 } } */
 
 #define NUM_VEC_ELEMS 4
 #define ITERS 16
 
-/*
-Codegen at time of writing is a single lxvrwx for the zero
-extended test, and a lwax,mtvsrdd,vextsd2q for the sign
-extended test.
-
-0000000010000c90 <test_sign_extended_load>:
-    10000c90:	aa 1a 24 7d 	lwax    r9,r4,r3
-    10000c94:	67 4b 40 7c 	mtvsrdd vs34,0,r9
-    10000c98:	02 16 5b 10 	vextsd2q v2,v2
-    10000c9c:	20 00 80 4e 	blr
-
-0000000010000cb0 <test_zero_extended_unsigned_load>:
-    10000cb0:	9b 18 44 7c 	lxvrwx  vs34,r4,r3
-    10000cb4:	20 00 80 4e 	blr
-*/
+/* Codegen at time of writing is a single lxvrwx for the zero extended test,
+   and a lxvrwx + vexts* sign extension instructions for the sign extended
+   test.
+
+   0000000000000000 <test_sign_extended_load>:
+	0:   9b 18 44 7c     lxvrwx  vs34,r4,r3
+	4:   02 16 5a 10     vextsw2d v2,v2
+	8:   02 16 5b 10     vextsd2q v2,v2
+	c:   20 00 80 4e     blr
+
+   0000000000000020 <test_zero_extended_unsigned_load>:
+	20:   9b 18 44 7c     lxvrwx  vs34,r4,r3
+	24:   20 00 80 4e     blr  */
 
 #include <altivec.h>
 #include <stdio.h>
diff --git a/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-short.c b/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-short.c
index 837ba79c9ab..a7721318812 100644
--- a/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-short.c
+++ b/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-short.c
@@ -6,33 +6,26 @@
 /* { dg-do compile { target { ! power10_hw } } } */
 /* { dg-require-effective-target power10_ok } */
 /* { dg-require-effective-target int128 } */
-
-/* Deliberately set optization to zero for this test to confirm
-   the lxvr*x instruction is generated. At higher optimization levels
-   the instruction we are looking for is sometimes replaced by other
-   load instructions.  */
-/* { dg-options "-mdejagnu-cpu=power10 -O0 -save-temps" } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2 -save-temps" } */
 
 /* { dg-final { scan-assembler-times {\mlxvrhx\M} 2 } } */
 
 #define NUM_VEC_ELEMS 8
 #define ITERS 16
 
-/*
-Codegen at time of writing uses lxvrhx for the zero
-extension test and lhax,mtvsrdd,vextsd2q for the
-sign extended test.
-
-0000000010001810 <test_sign_extended_load>:
-    10001810:	ae 1a 24 7d 	lhax    r9,r4,r3
-    10001814:	67 4b 40 7c 	mtvsrdd vs34,0,r9
-    10001818:	02 16 5b 10 	vextsd2q v2,v2
-    1000181c:	20 00 80 4e 	blr
-
-0000000010001830 <test_zero_extended_unsigned_load>:
-    10001830:	5b 18 44 7c 	lxvrhx  vs34,r4,r3
-    10001834:	20 00 80 4e 	blr
-*/
+/* Codegen at time of writing is a single lxvrwx for the zero extended test,
+   and a lxvrwx + vexts* sign extension instructions for the sign extended
+   test.
+
+	0000000000000000 <test_sign_extended_load>:
+	   0:   5b 18 44 7c     lxvrhx  vs34,r4,r3
+	   4:   02 16 59 10     vextsh2d v2,v2
+	   8:   02 16 5b 10     vextsd2q v2,v2
+	   c:   20 00 80 4e     blr
+
+	0000000000000020 <test_zero_extended_unsigned_load>:
+	  20:   5b 18 44 7c     lxvrhx  vs34,r4,r3
+	  24:   20 00 80 4e     blr  */
 
 #include <altivec.h>
 #include <stdio.h>
diff --git a/gcc/testsuite/gcc.target/powerpc/zero-extend-di-ti.c b/gcc/testsuite/gcc.target/powerpc/zero-extend-di-ti.c
new file mode 100644
index 00000000000..9b3b9c4dbd0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/zero-extend-di-ti.c
@@ -0,0 +1,62 @@
+/* { dg-require-effective-target int128     } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
+
+/* This patch makes sure the various optimization and code paths are done for
+   zero extending DImode to TImode on power10.  */
+
+__uint128_t
+gpr_to_gpr (unsigned long long a)
+{
+  /* li 4,0.  */
+  return a;
+}
+
+__uint128_t
+mem_to_gpr (unsigned long long *p)
+{
+  /* ld 3,0(3); li 4,0.  */
+  return *p;
+}
+
+__uint128_t
+vsx_to_gpr (__uint128_t *p, double d)
+{
+  /* fctiduz 1,1; li 4,0;mfvsrd 3,1.  */
+  return (unsigned long long)d;
+}
+
+void
+gpr_to_vsx (__uint128_t *p, unsigned long long a)
+{
+  /* mtvsrdd 0,0,4; stxv 0,0(3).  */
+  __uint128_t b = a;
+  __asm__ (" # %x0" : "+wa" (b));
+  *p = b;
+}
+
+void
+mem_to_vsx (__uint128_t *p, unsigned long long *q)
+{
+  /* lxvrdx 0,0,4; stxv 0,0(3).  */
+  __uint128_t a = *q;
+  __asm__ (" # %x0" : "+wa" (a));
+  *p = a;
+}
+
+void
+vsx_to_vsx (__uint128_t *p, double d)
+{
+  /* fctiduz 1,1; xxspltib 0,0; xxpermdi 0,0,1,0; stxv 0,0(3).  */
+  __uint128_t a = (unsigned long long)d;
+  __asm__ (" # %x0" : "+wa" (a));
+  *p = a;
+}
+
+/* { dg-final { scan-assembler-times {\mli\M}       3 } } */
+/* { dg-final { scan-assembler-times {\mld\M}       1 } } */
+/* { dg-final { scan-assembler-times {\mlxvrdx\M}   1 } } */
+/* { dg-final { scan-assembler-times {\mmfvsrd\M}   1 } } */
+/* { dg-final { scan-assembler-times {\mmtvsrdd\M}  1 } } */
+/* { dg-final { scan-assembler-times {\mstxv\M}     3 } } */
+/* { dg-final { scan-assembler-times {\mxxpermdi\M} 1 } } */