rs6000: Don't ICE when spilling an MMA accumulator

When we spill an accumulator that has a known zero value, LRA will emit
a new (set (reg:PXI ...) 0) insn, but it does not use the mma_xxsetaccz
pattern to do it, leading to an unrecognized insn ICE.  The solution here
is to move the xxsetaccz instruction into the movpxi pattern and have the
xxsetaccz pattern call the move pattern.

2020-08-06  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR target/96446
	* config/rs6000/mma.md (*movpxi): Add xxsetaccz generation.
	Disable split for zero constant source operand.
	(mma_xxsetaccz): Change to define_expand.  Call gen_movpxi.

gcc/testsuite/
	PR target/96446
	* gcc.target/powerpc/pr96446.c: New test.

diff --git a/gcc/config/rs6000/mma.md b/gcc/config/rs6000/mma.md
index 15cacfb7fc10f6ee16d6f20ec2e5a7672ba42ae4..a3fd28bdd0afc824b23b7e47781d248cdd8d1258 100644 (file)
--- a/gcc/config/rs6000/mma.md
+++ b/gcc/config/rs6000/mma.md
@@ -328,11 +328,15 @@
   [(set (match_operand:PXI 0 "nonimmediate_operand" "=d,m,d,d")
        (match_operand:PXI 1 "input_operand" "m,d,d,O"))]
   "TARGET_MMA
-   && ((gpc_reg_operand (operands[0], PXImode)
-       && !(CONST_INT_P (operands[1]) && INTVAL (operands[1]) == 0))
+   && (gpc_reg_operand (operands[0], PXImode)
        || gpc_reg_operand (operands[1], PXImode))"
-  "#"
-  "&& reload_completed"
+  "@
+   #
+   #
+   #
+   xxsetaccz %A0"
+  "&& reload_completed
+   && !(fpr_reg_operand (operands[0], PXImode) && operands[1] == const0_rtx)"
   [(const_int 0)]
 {
   rs6000_split_multireg_move (operands[0], operands[1]);
@@ -409,12 +413,14 @@
   "<acc> %A0"
   [(set_attr "type" "mma")])
 
-(define_insn "mma_xxsetaccz"
-  [(set (match_operand:PXI 0 "fpr_reg_operand" "=d")
+(define_expand "mma_xxsetaccz"
+  [(set (match_operand:PXI 0 "fpr_reg_operand")
        (const_int 0))]
   "TARGET_MMA"
-  "xxsetaccz %A0"
-  [(set_attr "type" "mma")])
+{
+  emit_insn (gen_movpxi (operands[0], const0_rtx));
+  DONE;
+})
 
 (define_insn "mma_<vv>"
   [(set (match_operand:PXI 0 "fpr_reg_operand" "=&d")

diff --git a/gcc/testsuite/gcc.target/powerpc/pr96446.c b/gcc/testsuite/gcc.target/powerpc/pr96446.c
new file mode 100644 (file)
index 0000000..2083bf4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr96446.c
@@ -0,0 +1,16 @@
+/* PR target/96466 */
+/* { dg-do compile } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
+
+/* Verify we do not ICE on the following.  */
+
+extern void bar0 (void);
+void
+foo0 (__vector_quad *dst)
+{
+  __vector_quad acc;
+  __builtin_mma_xxsetaccz (&acc);
+  bar0 ();
+  *dst = acc;
+}