[gcc r12-4494] Optimize the builtin vec_xl_sext

[gcc r12-4494] Optimize the builtin vec_xl_sext

[HaoChen Gui]

https://gcc.gnu.org/g:91419baf4d0075d11e3667b816c83687288163fd

commit r12-4494-g91419baf4d0075d11e3667b816c83687288163fd
Author: Haochen Gui <guihaoc@gcc.gnu.org>
Date:   Tue Oct 19 16:28:31 2021 +0800

    Optimize the builtin vec_xl_sext
    
    gcc/
            * config/rs6000/rs6000-call.c (altivec_expand_lxvr_builtin):
            Modify the expansion for sign extension. All extensions are done
            within VSX registers.
    
    gcc/testsuite/
            * gcc.target/powerpc/p10_vec_xl_sext.c: New test.

Diff:
---
 gcc/config/rs6000/rs6000-call.c                    | 33 +++++++++++++-------
 gcc/testsuite/gcc.target/powerpc/p10_vec_xl_sext.c | 35 ++++++++++++++++++++++
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index 2eceb2c71c0..6d8727c2bd8 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -9959,7 +9959,7 @@ altivec_expand_lxvr_builtin (enum insn_code icode, tree exp, rtx target, bool bl
 
   if (sign_extend)
     {
-      rtx discratch = gen_reg_rtx (DImode);
+      rtx discratch = gen_reg_rtx (V2DImode);
       rtx tiscratch = gen_reg_rtx (TImode);
 
       /* Emit the lxvr*x insn.  */
@@ -9968,20 +9968,31 @@ altivec_expand_lxvr_builtin (enum insn_code icode, tree exp, rtx target, bool bl
 	return 0;
       emit_insn (pat);
 
-      /* Emit a sign extension from QI,HI,WI to double (DI).  */
-      rtx scratch = gen_lowpart (smode, tiscratch);
+      /* Emit a sign extension from V16QI,V8HI,V4SI to V2DI.  */
+      rtx temp1, temp2;
       if (icode == CODE_FOR_vsx_lxvrbx)
-	emit_insn (gen_extendqidi2 (discratch, scratch));
+	{
+	  temp1  = simplify_gen_subreg (V16QImode, tiscratch, TImode, 0);
+	  emit_insn (gen_vsx_sign_extend_qi_v2di (discratch, temp1));
+	}
       else if (icode == CODE_FOR_vsx_lxvrhx)
-	emit_insn (gen_extendhidi2 (discratch, scratch));
+	{
+	  temp1  = simplify_gen_subreg (V8HImode, tiscratch, TImode, 0);
+	  emit_insn (gen_vsx_sign_extend_hi_v2di (discratch, temp1));
+	}
       else if (icode == CODE_FOR_vsx_lxvrwx)
-	emit_insn (gen_extendsidi2 (discratch, scratch));
-      /*  Assign discratch directly if scratch is already DI.  */
-      if (icode == CODE_FOR_vsx_lxvrdx)
-	discratch = scratch;
+	{
+	  temp1  = simplify_gen_subreg (V4SImode, tiscratch, TImode, 0);
+	  emit_insn (gen_vsx_sign_extend_si_v2di (discratch, temp1));
+	}
+      else if (icode == CODE_FOR_vsx_lxvrdx)
+	discratch = simplify_gen_subreg (V2DImode, tiscratch, TImode, 0);
+      else
+	gcc_unreachable ();
 
-      /* Emit the sign extension from DI (double) to TI (quad).  */
-      emit_insn (gen_extendditi2 (target, discratch));
+      /* Emit the sign extension from V2DI (double) to TI (quad).  */
+      temp2 = simplify_gen_subreg (TImode, discratch, V2DImode, 0);
+      emit_insn (gen_extendditi2_vector (target, temp2));
 
       return target;
     }
diff --git a/gcc/testsuite/gcc.target/powerpc/p10_vec_xl_sext.c b/gcc/testsuite/gcc.target/powerpc/p10_vec_xl_sext.c
new file mode 100644
index 00000000000..78e72ac5425
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/p10_vec_xl_sext.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target int128 } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
+
+#include <altivec.h>
+
+vector signed __int128
+foo1 (signed long a, signed char *b)
+{
+  return vec_xl_sext (a, b);
+}
+
+vector signed __int128
+foo2 (signed long a, signed short *b)
+{
+  return vec_xl_sext (a, b);
+}
+
+vector signed __int128
+foo3 (signed long a, signed int *b)
+{
+  return vec_xl_sext (a, b);
+}
+
+vector signed __int128
+foo4 (signed long a, signed long *b)
+{
+  return vec_xl_sext (a, b);
+}
+
+/* { dg-final { scan-assembler-times {\mvextsd2q\M} 4 } } */
+/* { dg-final { scan-assembler-times {\mvextsb2d\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mvextsh2d\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mvextsw2d\M} 1 } } */