[PATCH 4/8] PowerPC: Switch to dense math names for all MMA operations

[Michael Meissner <meissner@linux.ibm.com>]

This patch changes the assembler instruction names for MMA instructions from
the original name used in power10 to the new name when used with the dense math
system.  I.e. xvf64gerpp becomes dmxvf64gerpp.  The assembler will emit the
same bits for either spelling.

The patches have been tested on the following platforms.  I added the patches
for PR target/107299 that I submitted on November 2nd before doing the builds so
that GCC would build on systems using IEEE 128-bit long double.
    *	https://gcc.gnu.org/pipermail/gcc-patches/2022-November/604834.html

There were no regressions with doing bootstrap builds and running the regression
tests:

    1)	Power10 LE using --with-cpu=power10 --with-long-double-format=ieee;
    2)	Power10 LE using --with-cpu=power10 --with-long-double-format=ibm;
    3)	Power9 LE using --with-cpu=power9 --with-long-double-format=ibm; and
    4)	Power8 BE using --with-cpu=power8 (both 32-bit & 64-bit tested).

Note, I will be on vacation from Tuesday February 7th through Tuesday February
14th.

Can I check this patch into the GCC 13 master branch?

2023-02-03   Michael Meissner  <meissner@linux.ibm.com>

gcc/

	* config/rs6000/mma.md (vvi4i4i8_dm): New int attribute.
	(avvi4i4i8_dm): Likewise.
	(vvi4i4i2_dm): Likewise.
	(avvi4i4i2_dm): Likewise.
	(vvi4i4_dm): Likewise.
	(avvi4i4_dm): Likewise.
	(pvi4i2_dm): Likewise.
	(apvi4i2_dm): Likewise.
	(vvi4i4i4_dm): Likewise.
	(avvi4i4i4_dm): Likewise.
	(mma_<vv>): Add support for running on DMF systems, generating the dense
	math instruction and using the dense math accumulators.
	(mma_<avv>): Likewise.
	(mma_<pv>): Likewise.
	(mma_<apv>): Likewise.
	(mma_<vvi4i4i8>): Likewise.
	(mma_<avvi4i4i8>): Likewise.
	(mma_<vvi4i4i2>): Likewise.
	(mma_<avvi4i4i2>): Likewise.
	(mma_<vvi4i4>): Likewise.
	(mma_<avvi4i4): Likewise.
	(mma_<pvi4i2>): Likewise.
	(mma_<apvi4i2): Likewise.
	(mma_<vvi4i4i4>): Likewise.
	(mma_<avvi4i4i4>): Likewise.

gcc/testsuite/

	* gcc.target/powerpc/dm-double-test.c: New test.
	* lib/target-supports.exp (check_effective_target_ppc_dmr_ok): New
	target test.
---
 gcc/config/rs6000/mma.md                      |  98 +++++++--
 .../gcc.target/powerpc/dm-double-test.c       | 194 ++++++++++++++++++
 gcc/testsuite/lib/target-supports.exp         |  19 ++
 3 files changed, 299 insertions(+), 12 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/dm-double-test.c

diff --git a/gcc/config/rs6000/mma.md b/gcc/config/rs6000/mma.md
index 9e3feb3ea54..411e2345291 100644
--- a/gcc/config/rs6000/mma.md
+++ b/gcc/config/rs6000/mma.md
@@ -227,13 +227,22 @@ (define_int_attr apv		[(UNSPEC_MMA_XVF64GERPP		"xvf64gerpp")
 
 (define_int_attr vvi4i4i8	[(UNSPEC_MMA_PMXVI4GER8		"pmxvi4ger8")])
 
+(define_int_attr vvi4i4i8_dm	[(UNSPEC_MMA_PMXVI4GER8		"pmdmxvi4ger8")])
+
 (define_int_attr avvi4i4i8	[(UNSPEC_MMA_PMXVI4GER8PP	"pmxvi4ger8pp")])
 
+(define_int_attr avvi4i4i8_dm	[(UNSPEC_MMA_PMXVI4GER8PP	"pmdmxvi4ger8pp")])
+
 (define_int_attr vvi4i4i2	[(UNSPEC_MMA_PMXVI16GER2	"pmxvi16ger2")
 				 (UNSPEC_MMA_PMXVI16GER2S	"pmxvi16ger2s")
 				 (UNSPEC_MMA_PMXVF16GER2	"pmxvf16ger2")
 				 (UNSPEC_MMA_PMXVBF16GER2	"pmxvbf16ger2")])
 
+(define_int_attr vvi4i4i2_dm	[(UNSPEC_MMA_PMXVI16GER2	"pmdmxvi16ger2")
+				 (UNSPEC_MMA_PMXVI16GER2S	"pmdmxvi16ger2s")
+				 (UNSPEC_MMA_PMXVF16GER2	"pmdmxvf16ger2")
+				 (UNSPEC_MMA_PMXVBF16GER2	"pmdmxvbf16ger2")])
+
 (define_int_attr avvi4i4i2	[(UNSPEC_MMA_PMXVI16GER2PP	"pmxvi16ger2pp")
 				 (UNSPEC_MMA_PMXVI16GER2SPP	"pmxvi16ger2spp")
 				 (UNSPEC_MMA_PMXVF16GER2PP	"pmxvf16ger2pp")
@@ -245,25 +254,54 @@ (define_int_attr avvi4i4i2	[(UNSPEC_MMA_PMXVI16GER2PP	"pmxvi16ger2pp")
 				 (UNSPEC_MMA_PMXVBF16GER2NP	"pmxvbf16ger2np")
 				 (UNSPEC_MMA_PMXVBF16GER2NN	"pmxvbf16ger2nn")])
 
+(define_int_attr avvi4i4i2_dm	[(UNSPEC_MMA_PMXVI16GER2PP	"pmdmxvi16ger2pp")
+				 (UNSPEC_MMA_PMXVI16GER2SPP	"pmdmxvi16ger2spp")
+				 (UNSPEC_MMA_PMXVF16GER2PP	"pmdmxvf16ger2pp")
+				 (UNSPEC_MMA_PMXVF16GER2PN	"pmdmxvf16ger2pn")
+				 (UNSPEC_MMA_PMXVF16GER2NP	"pmdmxvf16ger2np")
+				 (UNSPEC_MMA_PMXVF16GER2NN	"pmdmxvf16ger2nn")
+				 (UNSPEC_MMA_PMXVBF16GER2PP	"pmdmxvbf16ger2pp")
+				 (UNSPEC_MMA_PMXVBF16GER2PN	"pmdmxvbf16ger2pn")
+				 (UNSPEC_MMA_PMXVBF16GER2NP	"pmdmxvbf16ger2np")
+				 (UNSPEC_MMA_PMXVBF16GER2NN	"pmdmxvbf16ger2nn")])
+
 (define_int_attr vvi4i4		[(UNSPEC_MMA_PMXVF32GER		"pmxvf32ger")])
 
+(define_int_attr vvi4i4_dm	[(UNSPEC_MMA_PMXVF32GER		"pmdmxvf32ger")])
+
 (define_int_attr avvi4i4	[(UNSPEC_MMA_PMXVF32GERPP	"pmxvf32gerpp")
 				 (UNSPEC_MMA_PMXVF32GERPN	"pmxvf32gerpn")
 				 (UNSPEC_MMA_PMXVF32GERNP	"pmxvf32gernp")
 				 (UNSPEC_MMA_PMXVF32GERNN	"pmxvf32gernn")])
 
+(define_int_attr avvi4i4_dm	[(UNSPEC_MMA_PMXVF32GERPP	"pmdmxvf32gerpp")
+				 (UNSPEC_MMA_PMXVF32GERPN	"pmdmxvf32gerpn")
+				 (UNSPEC_MMA_PMXVF32GERNP	"pmdmxvf32gernp")
+				 (UNSPEC_MMA_PMXVF32GERNN	"pmdmxvf32gernn")])
+
 (define_int_attr pvi4i2		[(UNSPEC_MMA_PMXVF64GER		"pmxvf64ger")])
 
+(define_int_attr pvi4i2_dm	[(UNSPEC_MMA_PMXVF64GER		"pmdmxvf64ger")])
+
 (define_int_attr apvi4i2	[(UNSPEC_MMA_PMXVF64GERPP	"pmxvf64gerpp")
 				 (UNSPEC_MMA_PMXVF64GERPN	"pmxvf64gerpn")
 				 (UNSPEC_MMA_PMXVF64GERNP	"pmxvf64gernp")
 				 (UNSPEC_MMA_PMXVF64GERNN	"pmxvf64gernn")])
 
+(define_int_attr apvi4i2_dm	[(UNSPEC_MMA_PMXVF64GERPP	"pmdmxvf64gerpp")
+				 (UNSPEC_MMA_PMXVF64GERPN	"pmdmxvf64gerpn")
+				 (UNSPEC_MMA_PMXVF64GERNP	"pmdmxvf64gernp")
+				 (UNSPEC_MMA_PMXVF64GERNN	"pmdmxvf64gernn")])
+
 (define_int_attr vvi4i4i4	[(UNSPEC_MMA_PMXVI8GER4		"pmxvi8ger4")])
 
+(define_int_attr vvi4i4i4_dm	[(UNSPEC_MMA_PMXVI8GER4		"pmdmxvi8ger4")])
+
 (define_int_attr avvi4i4i4	[(UNSPEC_MMA_PMXVI8GER4PP	"pmxvi8ger4pp")
 				 (UNSPEC_MMA_PMXVI8GER4SPP	"pmxvi8ger4spp")])
 
+(define_int_attr avvi4i4i4_dm	[(UNSPEC_MMA_PMXVI8GER4PP	"pmdmxvi8ger4pp")
+				 (UNSPEC_MMA_PMXVI8GER4SPP	"pmdmxvi8ger4spp")])
 
 ;; Vector pair support.  OOmode can only live in VSRs.
 (define_expand "movoo"
@@ -622,7 +660,10 @@ (define_insn "mma_<vv>"
 		    (match_operand:V16QI 2 "vsx_register_operand" "wa,v,?wa")]
 		    MMA_VV))]
   "TARGET_MMA"
-  "<vv> %A0,%x1,%x2"
+  "@
+   dm<vv> %A0,%x1,%x2
+   <vv> %A0,%x1,%x2
+   <vv> %A0,%x1,%x2"
   [(set_attr "type" "mma")
    (set_attr "isa" "dm,not_dm,not_dm")])
 
@@ -643,7 +684,10 @@ (define_insn "mma_<pv>"
 		    (match_operand:V16QI 2 "vsx_register_operand" "wa,v,?wa")]
 		    MMA_PV))]
   "TARGET_MMA"
-  "<pv> %A0,%x1,%x2"
+  "@
+   dm<pv> %A0,%x1,%x2
+   <pv> %A0,%x1,%x2
+   <pv> %A0,%x1,%x2"
   [(set_attr "type" "mma")
    (set_attr "isa" "dm,not_dm,not_dm")])
 
@@ -654,7 +698,10 @@ (define_insn "mma_<apv>"
 		    (match_operand:V16QI 3 "vsx_register_operand" "wa,v,?wa")]
 		    MMA_APV))]
   "TARGET_MMA"
-  "<apv> %A0,%x2,%x3"
+  "@
+   dm<apv> %A0,%x2,%x3
+   <apv> %A0,%x2,%x3
+   <apv> %A0,%x2,%x3"
   [(set_attr "type" "mma")
    (set_attr "isa" "dm,not_dm,not_dm")])
 
@@ -667,7 +714,10 @@ (define_insn "mma_<vvi4i4i8>"
 		    (match_operand:SI 5 "u8bit_cint_operand" "n,n,n")]
 		    MMA_VVI4I4I8))]
   "TARGET_MMA"
-  "<vvi4i4i8> %A0,%x1,%x2,%3,%4,%5"
+  "@
+   dm<vvi4i4i8> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i8> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i8> %A0,%x1,%x2,%3,%4,%5"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -696,7 +746,10 @@ (define_insn "mma_<vvi4i4i2>"
 		    (match_operand:SI 5 "const_0_to_3_operand" "n,n,n")]
 		    MMA_VVI4I4I2))]
   "TARGET_MMA"
-  "<vvi4i4i2> %A0,%x1,%x2,%3,%4,%5"
+  "@
+   <vvi4i4i2_dm> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i2> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i2> %A0,%x1,%x2,%3,%4,%5"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -711,7 +764,10 @@ (define_insn "mma_<avvi4i4i2>"
 		    (match_operand:SI 6 "const_0_to_3_operand" "n,n,n")]
 		    MMA_AVVI4I4I2))]
   "TARGET_MMA"
-  "<avvi4i4i2> %A0,%x2,%x3,%4,%5,%6"
+  "@
+   <avvi4i4i2_dm> %A0,%x2,%x3,%4,%5,%6
+   <avvi4i4i2> %A0,%x2,%x3,%4,%5,%6
+   <avvi4i4i2> %A0,%x2,%x3,%4,%5,%6"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -724,7 +780,10 @@ (define_insn "mma_<vvi4i4>"
 		    (match_operand:SI 4 "const_0_to_15_operand" "n,n,n")]
 		    MMA_VVI4I4))]
   "TARGET_MMA"
-  "<vvi4i4> %A0,%x1,%x2,%3,%4"
+  "@
+   <vvi4i4_dm> %A0,%x1,%x2,%3,%4
+   <vvi4i4> %A0,%x1,%x2,%3,%4
+   <vvi4i4> %A0,%x1,%x2,%3,%4"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -738,7 +797,10 @@ (define_insn "mma_<avvi4i4>"
 		    (match_operand:SI 5 "const_0_to_15_operand" "n,n,n")]
 		    MMA_AVVI4I4))]
   "TARGET_MMA"
-  "<avvi4i4> %A0,%x2,%x3,%4,%5"
+  "@
+   <avvi4i4_dm> %A0,%x2,%x3,%4,%5
+   <avvi4i4> %A0,%x2,%x3,%4,%5
+   <avvi4i4> %A0,%x2,%x3,%4,%5"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -751,7 +813,10 @@ (define_insn "mma_<pvi4i2>"
 		    (match_operand:SI 4 "const_0_to_3_operand" "n,n,n")]
 		    MMA_PVI4I2))]
   "TARGET_MMA"
-  "<pvi4i2> %A0,%x1,%x2,%3,%4"
+  "@
+   <pvi4i2_dm> %A0,%x1,%x2,%3,%4
+   <pvi4i2> %A0,%x1,%x2,%3,%4
+   <pvi4i2> %A0,%x1,%x2,%3,%4"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -765,7 +830,10 @@ (define_insn "mma_<apvi4i2>"
 		    (match_operand:SI 5 "const_0_to_3_operand" "n,n,n")]
 		    MMA_APVI4I2))]
   "TARGET_MMA"
-  "<apvi4i2> %A0,%x2,%x3,%4,%5"
+  "@
+   <apvi4i2_dm> %A0,%x2,%x3,%4,%5
+   <apvi4i2> %A0,%x2,%x3,%4,%5
+   <apvi4i2> %A0,%x2,%x3,%4,%5"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -779,7 +847,10 @@ (define_insn "mma_<vvi4i4i4>"
 		    (match_operand:SI 5 "const_0_to_15_operand" "n,n,n")]
 		    MMA_VVI4I4I4))]
   "TARGET_MMA"
-  "<vvi4i4i4> %A0,%x1,%x2,%3,%4,%5"
+  "@
+   <vvi4i4i4_dm> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i4> %A0,%x1,%x2,%3,%4,%5
+   <vvi4i4i4> %A0,%x1,%x2,%3,%4,%5"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
@@ -794,7 +865,10 @@ (define_insn "mma_<avvi4i4i4>"
 		    (match_operand:SI 6 "const_0_to_15_operand" "n,n,n")]
 		    MMA_AVVI4I4I4))]
   "TARGET_MMA"
-  "<avvi4i4i4> %A0,%x2,%x3,%4,%5,%6"
+  "@
+   <avvi4i4i4_dm> %A0,%x2,%x3,%4,%5,%6
+   <avvi4i4i4> %A0,%x2,%x3,%4,%5,%6
+   <avvi4i4i4> %A0,%x2,%x3,%4,%5,%6"
   [(set_attr "type" "mma")
    (set_attr "prefixed" "yes")
    (set_attr "isa" "dm,not_dm,not_dm")])
diff --git a/gcc/testsuite/gcc.target/powerpc/dm-double-test.c b/gcc/testsuite/gcc.target/powerpc/dm-double-test.c
new file mode 100644
index 00000000000..66c19779585
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/dm-double-test.c
@@ -0,0 +1,194 @@
+/* Test derived from mma-double-1.c, modified for dense math.  */
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_dense_math_ok } */
+/* { dg-options "-mdejagnu-cpu=future -O2" } */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <altivec.h>
+
+typedef unsigned char vec_t __attribute__ ((vector_size (16)));
+typedef double v4sf_t __attribute__ ((vector_size (16)));
+#define SAVE_ACC(ACC, ldc, J)  \
+	  __builtin_mma_disassemble_acc (result, ACC); \
+	  rowC = (v4sf_t *) &CO[0*ldc+J]; \
+          rowC[0] += result[0]; \
+          rowC = (v4sf_t *) &CO[1*ldc+J]; \
+          rowC[0] += result[1]; \
+          rowC = (v4sf_t *) &CO[2*ldc+J]; \
+          rowC[0] += result[2]; \
+          rowC = (v4sf_t *) &CO[3*ldc+J]; \
+	  rowC[0] += result[3];
+
+void
+DM (int m, int n, int k, double *A, double *B, double *C)
+{
+  __vector_quad acc0, acc1, acc2, acc3, acc4, acc5, acc6, acc7;
+  v4sf_t result[4];
+  v4sf_t *rowC;
+  for (int l = 0; l < n; l += 4)
+    {
+      double *CO;
+      double *AO;
+      AO = A;
+      CO = C;
+      C += m * 4;
+      for (int j = 0; j < m; j += 16)
+	{
+	  double *BO = B;
+	  __builtin_mma_xxsetaccz (&acc0);
+	  __builtin_mma_xxsetaccz (&acc1);
+	  __builtin_mma_xxsetaccz (&acc2);
+	  __builtin_mma_xxsetaccz (&acc3);
+	  __builtin_mma_xxsetaccz (&acc4);
+	  __builtin_mma_xxsetaccz (&acc5);
+	  __builtin_mma_xxsetaccz (&acc6);
+	  __builtin_mma_xxsetaccz (&acc7);
+	  unsigned long i;
+
+	  for (i = 0; i < k; i++)
+	    {
+	      vec_t *rowA = (vec_t *) & AO[i * 16];
+	      __vector_pair rowB;
+	      vec_t *rb = (vec_t *) & BO[i * 4];
+	      __builtin_mma_assemble_pair (&rowB, rb[1], rb[0]);
+	      __builtin_mma_xvf64gerpp (&acc0, rowB, rowA[0]);
+	      __builtin_mma_xvf64gerpp (&acc1, rowB, rowA[1]);
+	      __builtin_mma_xvf64gerpp (&acc2, rowB, rowA[2]);
+	      __builtin_mma_xvf64gerpp (&acc3, rowB, rowA[3]);
+	      __builtin_mma_xvf64gerpp (&acc4, rowB, rowA[4]);
+	      __builtin_mma_xvf64gerpp (&acc5, rowB, rowA[5]);
+	      __builtin_mma_xvf64gerpp (&acc6, rowB, rowA[6]);
+	      __builtin_mma_xvf64gerpp (&acc7, rowB, rowA[7]);
+	    }
+	  SAVE_ACC (&acc0, m, 0);
+	  SAVE_ACC (&acc2, m, 4);
+	  SAVE_ACC (&acc1, m, 2);
+	  SAVE_ACC (&acc3, m, 6);
+	  SAVE_ACC (&acc4, m, 8);
+	  SAVE_ACC (&acc6, m, 12);
+	  SAVE_ACC (&acc5, m, 10);
+	  SAVE_ACC (&acc7, m, 14);
+	  AO += k * 16;
+	  BO += k * 4;
+	  CO += 16;
+	}
+      B += k * 4;
+    }
+}
+
+void
+init (double *matrix, int row, int column)
+{
+  for (int j = 0; j < column; j++)
+    {
+      for (int i = 0; i < row; i++)
+	{
+	  matrix[j * row + i] = (i * 16 + 2 + j) / 0.123;
+	}
+    }
+}
+
+void
+init0 (double *matrix, double *matrix1, int row, int column)
+{
+  for (int j = 0; j < column; j++)
+    for (int i = 0; i < row; i++)
+      matrix[j * row + i] = matrix1[j * row + i] = 0;
+}
+
+
+void
+print (const char *name, const double *matrix, int row, int column)
+{
+  printf ("Matrix %s has %d rows and %d columns:\n", name, row, column);
+  for (int i = 0; i < row; i++)
+    {
+      for (int j = 0; j < column; j++)
+	{
+	  printf ("%f ", matrix[j * row + i]);
+	}
+      printf ("\n");
+    }
+  printf ("\n");
+}
+
+int
+main (int argc, char *argv[])
+{
+  int rowsA, colsB, common;
+  int i, j, k;
+  int ret = 0;
+
+  for (int t = 16; t <= 128; t += 16)
+    {
+      for (int t1 = 4; t1 <= 16; t1 += 4)
+	{
+	  rowsA = t;
+	  colsB = t1;
+	  common = 1;
+	  /* printf ("Running test for rows = %d,cols = %d\n", t, t1); */
+	  double A[rowsA * common];
+	  double B[common * colsB];
+	  double C[rowsA * colsB];
+	  double D[rowsA * colsB];
+
+
+	  init (A, rowsA, common);
+	  init (B, common, colsB);
+	  init0 (C, D, rowsA, colsB);
+	  DM (rowsA, colsB, common, A, B, C);
+
+	  for (i = 0; i < colsB; i++)
+	    {
+	      for (j = 0; j < rowsA; j++)
+		{
+		  D[i * rowsA + j] = 0;
+		  for (k = 0; k < common; k++)
+		    {
+		      D[i * rowsA + j] +=
+			A[k * rowsA + j] * B[k + common * i];
+		    }
+		}
+	    }
+	  for (i = 0; i < colsB; i++)
+	    {
+	      for (j = 0; j < rowsA; j++)
+		{
+		  for (k = 0; k < common; k++)
+		    {
+		      if (D[i * rowsA + j] != C[i * rowsA + j])
+			{
+			  printf ("Error %d,%d,%d\n",i,j,k);
+			  ret++;
+			}
+		    }
+		}
+	    }
+	  if (ret)
+	    {
+	      print ("A", A, rowsA, common);
+	      print ("B", B, common, colsB);
+	      print ("C", C, rowsA, colsB);
+	      print ("D", D, rowsA, colsB);
+	    }
+	}
+    }
+  
+#ifdef VERBOSE
+  if (ret)
+    printf ("DM double test fail: %d errors\n",ret);
+  else
+    printf ("DM double test success: 0 DM errors\n");
+#else
+  if (ret)
+    abort();
+#endif
+      
+  return ret;
+}
+
+/* { dg-final { scan-assembler {\mdmsetdmrz\M}      } } */
+/* { dg-final { scan-assembler {\mdmxvf64gerpp\M}   } } */
+/* { dg-final { scan-assembler {\mdmxxextfdmr512\M} } } */
+
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 227e3004077..9586ed3ae47 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6581,6 +6581,25 @@ proc check_effective_target_power10_ok { } {
     }
 }
 
+# Return 1 if this is a PowerPC target supporting -mcpu=future or -mdense-math
+# which enables the dense math operations.
+proc check_effective_target_powerpc_dense_math_ok { } {
+	return [check_no_compiler_messages_nocache powerpc_dense_math_ok assembly {
+		__vector_quad vq;
+		void test (void)
+		{
+		#ifndef __PPC_DMR__
+		#error "target does not have dense math support."
+		#else
+		/* Make sure we have dense math support.  */
+		  __vector_quad dmr;
+		  __asm__ ("dmsetaccz %A0" : "=wD" (dmr));
+		  vq = dmr;
+		#endif
+		}
+	} "-mcpu=future"]
+}
+
 # Return 1 if this is a PowerPC target supporting -mfloat128 via either
 # software emulation on power7/power8 systems or hardware support on power9.
 
-- 
2.39.1


-- 
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meissner@linux.ibm.com