rs6000: Add new __builtin_vsx_build_pair and __builtin_mma_build_acc built-ins

The __builtin_vsx_assemble_pair and __builtin_mma_assemble_acc built-ins
currently assign their first source operand to the first VSX register
in a pair/quad, their second operand to the second register in a pair/quad, etc.
This is not endian friendly and forces the user to generate different calls
depending on endianness.  In agreement with the POWER LLVM team, we've
decided to lightly deprecate the assemble built-ins and replace them with
"build" built-ins that automatically handle endianness so the same built-in
call and be used for both little-endian and big-endian compiles.  We are not
removing the assemble built-ins, since there is code in the wild that use
them, but we are removing their documentation to encourage the use of the
new "build" variants.

gcc/
	* config/rs6000/rs6000-builtin.def (build_pair): New built-in.
	(build_acc): Likewise.
	* config/rs6000/rs6000-call.c (mma_expand_builtin): Swap assemble
	source operands in little-endian mode.
	(rs6000_gimple_fold_mma_builtin): Handle VSX_BUILTIN_BUILD_PAIR.
	(mma_init_builtins): Likewise.
	* config/rs6000/rs6000.c (rs6000_split_multireg_move): Handle endianness
	ordering for the MMA assemble and build source operands.
	* doc/extend.texi (__builtin_vsx_build_acc, __builtin_mma_build_pair):
	Document.
	(__builtin_mma_assemble_acc, __builtin_mma_assemble_pair): Remove
	documentation.

gcc/testsuite/
	* gcc.target/powerpc/mma-builtin-4.c (__builtin_vsx_build_pair): Add
	tests.  Update expected counts.
	* gcc.target/powerpc/mma-builtin-5.c (__builtin_mma_build_acc): Add
	tests.  Update expected counts.

6 files changed, 58 insertions, 13 deletions

diff --git a/gcc/config/rs6000/rs6000-builtin.def b/gcc/config/rs6000/rs6000-builtin.def
index d55095b..231e7c9 100644
--- a/gcc/config/rs6000/rs6000-builtin.def
+++ b/gcc/config/rs6000/rs6000-builtin.def
@@ -3265,6 +3265,7 @@ BU_MMA_2 (DISASSEMBLE_ACC, "disassemble_acc",	QUAD, mma_disassemble_acc)
 BU_MMA_V2 (DISASSEMBLE_PAIR, "disassemble_pair", PAIR, vsx_disassemble_pair)
 BU_COMPAT (VSX_BUILTIN_DISASSEMBLE_PAIR, "mma_disassemble_pair")
 
+BU_MMA_V3 (BUILD_PAIR,	    "build_pair",	MISC, vsx_assemble_pair)
 BU_MMA_V3 (ASSEMBLE_PAIR,   "assemble_pair",	MISC, vsx_assemble_pair)
 BU_COMPAT (VSX_BUILTIN_ASSEMBLE_PAIR, "mma_assemble_pair")
 BU_MMA_3 (XVBF16GER2,	    "xvbf16ger2",	MISC, mma_xvbf16ger2)
@@ -3297,6 +3298,7 @@ BU_MMA_3 (XVI8GER4SPP,	    "xvi8ger4spp",      QUAD, mma_xvi8ger4spp)
 BU_MMA_3 (XVI16GER2PP,	    "xvi16ger2pp",      QUAD, mma_xvi16ger2pp)
 BU_MMA_3 (XVI16GER2SPP,	    "xvi16ger2spp",     QUAD, mma_xvi16ger2spp)
 
+BU_MMA_5 (BUILD_ACC,	    "build_acc",	MISC, mma_assemble_acc)
 BU_MMA_5 (ASSEMBLE_ACC,     "assemble_acc",	MISC, mma_assemble_acc)
 BU_MMA_5 (PMXVF32GER,	    "pmxvf32ger",       MISC, mma_pmxvf32ger)
 BU_MMA_5 (PMXVF64GER,	    "pmxvf64ger",       PAIR, mma_pmxvf64ger)
diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index b0b7f12..0ac6b6e 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -10244,12 +10244,23 @@ mma_expand_builtin (tree exp, rtx target, bool *expandedp)
       pat = GEN_FCN (icode) (op[0], op[1]);
       break;
     case 3:
+      /* The ASSEMBLE builtin source operands are reversed in little-endian
+	 mode, so reorder them.  */
+      if (fcode == VSX_BUILTIN_ASSEMBLE_PAIR_INTERNAL && !WORDS_BIG_ENDIAN)
+	std::swap (op[1], op[2]);
       pat = GEN_FCN (icode) (op[0], op[1], op[2]);
       break;
     case 4:
       pat = GEN_FCN (icode) (op[0], op[1], op[2], op[3]);
       break;
     case 5:
+      /* The ASSEMBLE builtin source operands are reversed in little-endian
+	 mode, so reorder them.  */
+      if (fcode == MMA_BUILTIN_ASSEMBLE_ACC_INTERNAL && !WORDS_BIG_ENDIAN)
+	{
+	  std::swap (op[1], op[4]);
+	  std::swap (op[2], op[3]);
+	}
       pat = GEN_FCN (icode) (op[0], op[1], op[2], op[3], op[4]);
       break;
     case 6:
@@ -11961,7 +11972,7 @@ rs6000_gimple_fold_mma_builtin (gimple_stmt_iterator *gsi)
       gcc_unreachable ();
     }
 
-  if (fncode == VSX_BUILTIN_ASSEMBLE_PAIR)
+  if (fncode == VSX_BUILTIN_BUILD_PAIR || fncode == VSX_BUILTIN_ASSEMBLE_PAIR)
     lhs = make_ssa_name (vector_pair_type_node);
   else
     lhs = make_ssa_name (vector_quad_type_node);
@@ -14293,8 +14304,10 @@ mma_init_builtins (void)
 	      machine_mode mode = insn_data[icode].operand[j].mode;
 	      if (gimple_func && mode == XOmode)
 		op[nopnds++] = build_pointer_type (vector_quad_type_node);
-	      else if (gimple_func && mode == OOmode
-		       && d->code == VSX_BUILTIN_ASSEMBLE_PAIR)
+	      else if (gimple_func
+		       && mode == OOmode
+		       && (d->code == VSX_BUILTIN_BUILD_PAIR
+			   || d->code == VSX_BUILTIN_ASSEMBLE_PAIR))
 		op[nopnds++] = build_pointer_type (vector_pair_type_node);
 	      else
 		/* MMA uses unsigned types.  */
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 75c2cc4..38f9281 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -16807,9 +16807,11 @@ rs6000_split_multireg_move (rtx dst, rtx src)
 	    gcc_assert (VSX_REGNO_P (REGNO (dst)));
 
 	  reg_mode = GET_MODE (XVECEXP (src, 0, 0));
-	  for (int i = 0; i < XVECLEN (src, 0); i++)
+	  int nvecs = XVECLEN (src, 0);
+	  for (int i = 0; i < nvecs; i++)
 	    {
-	      rtx dst_i = gen_rtx_REG (reg_mode, reg + i);
+	      int index = WORDS_BIG_ENDIAN ? i : nvecs - 1 - i;
+	      rtx dst_i = gen_rtx_REG (reg_mode, reg + index);
 	      emit_insn (gen_rtx_SET (dst_i, XVECEXP (src, 0, i)));
 	    }
 
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index c24ecd7..408979b 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -20723,10 +20723,10 @@ void __builtin_mma_xxmtacc (__vector_quad *);
 void __builtin_mma_xxmfacc (__vector_quad *);
 void __builtin_mma_xxsetaccz (__vector_quad *);
 
-void __builtin_mma_assemble_acc (__vector_quad *, vec_t, vec_t, vec_t, vec_t);
+void __builtin_mma_build_acc (__vector_quad *, vec_t, vec_t, vec_t, vec_t);
 void __builtin_mma_disassemble_acc (void *, __vector_quad *);
 
-void __builtin_vsx_assemble_pair (__vector_pair *, vec_t, vec_t);
+void __builtin_vsx_build_pair (__vector_pair *, vec_t, vec_t);
 void __builtin_vsx_disassemble_pair (void *, __vector_pair *);
 
 vec_t __builtin_vsx_xvcvspbf16 (vec_t);
diff --git a/gcc/testsuite/gcc.target/powerpc/mma-builtin-4.c b/gcc/testsuite/gcc.target/powerpc/mma-builtin-4.c
index 3bedf53..a9fb010 100644
--- a/gcc/testsuite/gcc.target/powerpc/mma-builtin-4.c
+++ b/gcc/testsuite/gcc.target/powerpc/mma-builtin-4.c
@@ -21,6 +21,14 @@ foo2 (__vector_pair *dst, vec_t *src)
 }
 
 void
+foo3 (__vector_pair *dst, vec_t *src)
+{
+  __vector_pair pair;
+  __builtin_vsx_build_pair (&pair, src[4], src[0]);
+  *dst = pair;
+}
+
+void
 bar (vec_t *dst, __vector_pair *src)
 {
   vec_t res[2];
@@ -54,8 +62,12 @@ bar2 (vec_t *dst, __vector_pair *src)
 #  error "__has_builtin (__builtin_mma_disassemble_pair) failed"
 #endif
 
-/* { dg-final { scan-assembler-times {\mlxv\M} 4 } } */
+#if !__has_builtin (__builtin_vsx_build_pair)
+#  error "__has_builtin (__builtin_vsx_build_pair) failed"
+#endif
+
+/* { dg-final { scan-assembler-times {\mlxv\M} 6 } } */
 /* { dg-final { scan-assembler-times {\mlxvp\M} 2 } } */
 /* { dg-final { scan-assembler-times {\mstxv\M} 4 } } */
-/* { dg-final { scan-assembler-times {\mstxvp\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mstxvp\M} 3 } } */
 
diff --git a/gcc/testsuite/gcc.target/powerpc/mma-builtin-5.c b/gcc/testsuite/gcc.target/powerpc/mma-builtin-5.c
index 43b6d3a..00503b7 100644
--- a/gcc/testsuite/gcc.target/powerpc/mma-builtin-5.c
+++ b/gcc/testsuite/gcc.target/powerpc/mma-builtin-5.c
@@ -13,6 +13,14 @@ foo (__vector_quad *dst, vec_t *src)
 }
 
 void
+foo2 (__vector_quad *dst, vec_t *src)
+{
+  __vector_quad acc;
+  __builtin_mma_build_acc (&acc, src[12], src[8], src[4], src[0]);
+  *dst = acc;
+}
+
+void
 bar (vec_t *dst, __vector_quad *src)
 {
   vec_t res[4];
@@ -23,9 +31,17 @@ bar (vec_t *dst, __vector_quad *src)
   dst[12] = res[3];
 }
 
-/* { dg-final { scan-assembler-times {\mlxv\M} 4 } } */
+#if !__has_builtin (__builtin_mma_assemble_acc)
+#  error "__has_builtin (__builtin_mma_assemble_acc) failed"
+#endif
+
+#if !__has_builtin (__builtin_mma_build_acc)
+#  error "__has_builtin (__builtin_mma_build_acc) failed"
+#endif
+
+/* { dg-final { scan-assembler-times {\mlxv\M} 8 } } */
 /* { dg-final { scan-assembler-times {\mlxvp\M} 2 } } */
 /* { dg-final { scan-assembler-times {\mstxv\M} 4 } } */
-/* { dg-final { scan-assembler-times {\mstxvp\M} 2 } } */
-/* { dg-final { scan-assembler-times {\mxxmfacc\M} 2 } } */
-/* { dg-final { scan-assembler-times {\mxxmtacc\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mstxvp\M} 4 } } */
+/* { dg-final { scan-assembler-times {\mxxmfacc\M} 3 } } */
+/* { dg-final { scan-assembler-times {\mxxmtacc\M} 3 } } */