[gcc(refs/users/meissner/heads/work119)] Optimize variable element vec_extract to be converted to floating point

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:f0f4835b6845fd3d207afd124d3defd25428a67d

commit f0f4835b6845fd3d207afd124d3defd25428a67d
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Sat Apr 29 00:06:39 2023 -0400

    Optimize variable element vec_extract to be converted to floating point
    
    This patch optimizes vec_extract with a variable element number of the following
    types to be converted to floating point by loading the value directly to the
    vector register, and then doing the conversion instead of loading the value to a
    GPR and then doing a direct move:
    
    vector int
    vector unsigned int
    vector unsigned short
    vector unsigned char
    
    2023-04-28   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            * config/rs6000/vsx.md (vsx_extract_v4si_var_load_to_<uns><mode>): New
            * insn.
            * vsx_extract_<VSX_EXTRACT_I2:mode>_var_load_to_uns<SFDF:mode>: New
            insn.
    
    gcc/testsuite/
    
            * gcc.target/powerpc/vec-extract-mem-int-6.c: New file.
            * gcc.target/powerpc/vec-extract-mem-int_7.c: New file.

Diff:
---
 gcc/config/rs6000/vsx.md                           | 52 ++++++++++++++++++++++
 .../gcc.target/powerpc/vec-extract-mem-int-6.c     | 29 ++++++++++++
 .../gcc.target/powerpc/vec-extract-mem-int-7.c     | 29 ++++++++++++
 3 files changed, 110 insertions(+)

diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index 559a7034367..d156c9bd90b 100644
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -4295,6 +4295,58 @@
 }
   [(set_attr "type" "load")])
 
+;; Fold extracting a V4SI element with a variable element with either sign or
+;; zero extension to SFmode or DFmode into LFIWAX/LFIWZX and FCFID.
+(define_insn_and_split "*vsx_extract_v4si_var_load_to_<uns><mode>"
+  [(set (match_operand:SFDF 0 "register_operand" "=wa")
+	(any_float:SFDF
+	 (unspec:SI
+	  [(match_operand:V4SI 1 "memory_operand" "Q")
+	   (match_operand:DI 2 "register_operand" "r")]
+	  UNSPEC_VSX_EXTRACT)))
+   (clobber (match_scratch:DI 3 "=&b"))
+   (clobber (match_scratch:DI 4 "=wa"))]
+  "VECTOR_MEM_VSX_P (V4SImode) && TARGET_DIRECT_MOVE_64BIT"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 4)
+	(<fp_int_extend>:DI (match_dup 5)))
+   (set (match_dup 0)
+	(float:SFDF (match_dup 4)))]
+{
+  operands[5] = rs6000_adjust_vec_address (operands[0], operands[1],
+					   operands[2], operands[3],
+					   SImode);
+}
+  [(set_attr "type" "fpload")
+   (set_attr "length" "8")])
+
+;; Fold extracting a V8HI/V16QI element with a variable element with zero
+;; extension to SFmode or DFmode into LXSIBZX/LXSIHZX and FCFID
+(define_insn_and_split "*vsx_extract_<VSX_EXTRACT_I2:mode>_var_load_to_uns<SFDF:mode>"
+  [(set (match_operand:SFDF 0 "register_operand" "=wa")
+	(unsigned_float:SFDF
+	 (unspec:<VSX_EXTRACT_I2:VEC_base>
+	  [(match_operand:VSX_EXTRACT_I2 1 "memory_operand" "Q")
+	   (match_operand:DI 2 "register_operand" "r")]
+	  UNSPEC_VSX_EXTRACT)))
+   (clobber (match_scratch:DI 3 "=&b"))
+   (clobber (match_scratch:DI 4 "=v"))]
+  "VECTOR_MEM_VSX_P (<VSX_EXTRACT_I2:MODE>mode) && TARGET_P9_VECTOR"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 4)
+	(zero_extend:DI (match_dup 5)))
+   (set (match_dup 0)
+	(float:SFDF (match_dup 4)))]
+{
+  operands[5] = rs6000_adjust_vec_address (operands[0], operands[1],
+					   operands[2], operands[3],
+					   <VSX_EXTRACT_I2:VEC_base>mode);
+}
+  [(set_attr "type" "fpload")
+   (set_attr "length" "8")])
+
 ;; ISA 3.1 extract
 (define_expand "vextractl<mode>"
   [(set (match_operand:V2DI 0 "altivec_register_operand")
diff --git a/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-6.c b/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-6.c
new file mode 100644
index 00000000000..e08a3587eb2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-6.c
@@ -0,0 +1,29 @@
+/* { dg-do compile { target lp64 } } */
+/* { dg-require-effective-target powerpc_p8vector_ok } */
+/* { dg-options "-mdejagnu-cpu=power8 -O2" } */
+
+/* Test to verify that the vec_extract with variable element numbers can load
+   SImode and convert it to unsigned floating point, by loading the value
+   directly to a vector register, rather than loading up a GPR and transfering
+   the result to a vector register.  */
+
+#include <altivec.h>
+#include <stddef.h>
+
+double
+extract_dbl_uns_v4si_n (vector unsigned int *p, size_t n)
+{
+  return vec_extract (*p, n);	/* lfiwzx/lxsiwzx, fcfid/xscvsxddp.  */
+}
+
+float
+extract_flt_uns_v4si_element_n_index_4 (vector unsigned int *p, size_t n)
+{
+  return vec_extract (p[4], n);	/* lfiwzx/lxsiwzx, fcfids/xscvsxdsp.  */
+}
+
+/* { dg-final { scan-assembler-times {\mlfiwzx\M|\mlxsiwzx\M}   2 } } */
+/* { dg-final { scan-assembler-times {\mfcfid\M|\mxscvsxddp\M}  1 } } */
+/* { dg-final { scan-assembler-times {\mfcfids\M|\mxscvsxdsp\M} 1 } } */
+/* { dg-final { scan-assembler-not   {\mlw[az]x?\M}               } } */
+/* { dg-final { scan-assembler-not   {\mmtvsr}                    } } */
diff --git a/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-7.c b/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-7.c
new file mode 100644
index 00000000000..ddba763a395
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/vec-extract-mem-int-7.c
@@ -0,0 +1,29 @@
+/* { dg-do compile { target lp64 } } */
+/* { dg-require-effective-target powerpc_p8vector_ok } */
+/* { dg-options "-mdejagnu-cpu=power8 -O2" } */
+
+/* Test to verify that the vec_extract with variable element numbers can load
+   SImode and convert it to signed floating point, by loading the value
+   directly to a vector register, rather than loading up a GPR and transfering
+   the result to a vector register.  */
+
+#include <altivec.h>
+#include <stddef.h>
+
+double
+extract_dbl_sign_v4si_n (vector int *p, size_t n)
+{
+  return vec_extract (*p, n);	/* lfiwzx/lxsiwzx, fcfid/xscvsxddp.  */
+}
+
+float
+extract_flt_sign_v4si_element_n_index_4 (vector int *p, size_t n)
+{
+  return vec_extract (p[4], n);	/* lfiwzx/lxsiwzx, fcfids/xscvsxdsp.  */
+}
+
+/* { dg-final { scan-assembler-times {\mlfiwax\M|\mlxsiwax\M}   2 } } */
+/* { dg-final { scan-assembler-times {\mfcfid\M|\mxscvsxddp\M}  1 } } */
+/* { dg-final { scan-assembler-times {\mfcfids\M|\mxscvsxdsp\M} 1 } } */
+/* { dg-final { scan-assembler-not   {\mlw[az]x?\M}               } } */
+/* { dg-final { scan-assembler-not   {\mmtvsr}                    } } */