IBM Z: Fix long double <-> DFP conversions

When switching the s390 backend to store long doubles in vector
registers, the patterns for long double <-> DFP conversions were
forgotten.  This did not cause observable problems so far, because
libdfp calls are emitted instead of pfpo.  However, when building
libdfp itself, this leads to infinite recursion.

gcc/ChangeLog:

	PR target/99134
	* config/s390/vector.md (trunctf<DFP_ALL:mode>2_vr): New
	pattern.
	(trunctf<DFP_ALL:mode>2): Likewise.
	(trunctdtf2_vr): Likewise.
	(trunctdtf2): Likewise.
	(extend<DFP_ALL:mode>tf2_vr): Likewise.
	(extend<DFP_ALL:mode>tf2): Likewise.
	(extendtftd2_vr): Likewise.
	(extendtftd2): Likewise.

gcc/testsuite/ChangeLog:

	PR target/99134
	* gcc.target/s390/vector/long-double-from-decimal128.c: New test.
	* gcc.target/s390/vector/long-double-from-decimal32.c: New test.
	* gcc.target/s390/vector/long-double-from-decimal64.c: New test.
	* gcc.target/s390/vector/long-double-to-decimal128.c: New test.
	* gcc.target/s390/vector/long-double-to-decimal32.c: New test.
	* gcc.target/s390/vector/long-double-to-decimal64.c: New test.

gcc/config/s390/vector.md

@@ -2480,6 +2480,42 @@
   "HAVE_TF (trunctfsf2)"
   { EXPAND_TF (trunctfsf2, 2); })
 
+(define_expand "trunctf<DFP_ALL:mode>2_vr"
+  [(match_operand:DFP_ALL 0 "nonimmediate_operand" "")
+   (match_operand:TF 1 "nonimmediate_operand" "")]
+  "TARGET_HARD_DFP
+   && GET_MODE_SIZE (TFmode) > GET_MODE_SIZE (<DFP_ALL:MODE>mode)
+   && TARGET_VXE"
+{
+  rtx fprx2 = gen_reg_rtx (FPRX2mode);
+  emit_insn (gen_tf_to_fprx2 (fprx2, operands[1]));
+  emit_insn (gen_truncfprx2<DFP_ALL:mode>2 (operands[0], fprx2));
+  DONE;
+})
+
+(define_expand "trunctf<DFP_ALL:mode>2"
+  [(match_operand:DFP_ALL 0 "nonimmediate_operand" "")
+   (match_operand:TF 1 "nonimmediate_operand" "")]
+  "HAVE_TF (trunctf<DFP_ALL:mode>2)"
+  { EXPAND_TF (trunctf<DFP_ALL:mode>2, 2); })
+
+(define_expand "trunctdtf2_vr"
+  [(match_operand:TF 0 "nonimmediate_operand" "")
+   (match_operand:TD 1 "nonimmediate_operand" "")]
+  "TARGET_HARD_DFP && TARGET_VXE"
+{
+  rtx fprx2 = gen_reg_rtx (FPRX2mode);
+  emit_insn (gen_trunctdfprx22 (fprx2, operands[1]));
+  emit_insn (gen_fprx2_to_tf (operands[0], fprx2));
+  DONE;
+})
+
+(define_expand "trunctdtf2"
+  [(match_operand:TF 0 "nonimmediate_operand" "")
+   (match_operand:TD 1 "nonimmediate_operand" "")]
+  "HAVE_TF (trunctdtf2)"
+  { EXPAND_TF (trunctdtf2, 2); })
+
 ; load lengthened
 
 (define_insn "extenddftf2_vr"
@@ -2511,6 +2547,42 @@
   "HAVE_TF (extendsftf2)"
   { EXPAND_TF (extendsftf2, 2); })
 
+(define_expand "extend<DFP_ALL:mode>tf2_vr"
+  [(match_operand:TF 0 "nonimmediate_operand" "")
+   (match_operand:DFP_ALL 1 "nonimmediate_operand" "")]
+  "TARGET_HARD_DFP
+   && GET_MODE_SIZE (<DFP_ALL:MODE>mode) < GET_MODE_SIZE (TFmode)
+   && TARGET_VXE"
+{
+  rtx fprx2 = gen_reg_rtx (FPRX2mode);
+  emit_insn (gen_extend<DFP_ALL:mode>fprx22 (fprx2, operands[1]));
+  emit_insn (gen_fprx2_to_tf (operands[0], fprx2));
+  DONE;
+})
+
+(define_expand "extend<DFP_ALL:mode>tf2"
+  [(match_operand:TF 0 "nonimmediate_operand" "")
+   (match_operand:DFP_ALL 1 "nonimmediate_operand" "")]
+  "HAVE_TF (extend<DFP_ALL:mode>tf2)"
+  { EXPAND_TF (extend<DFP_ALL:mode>tf2, 2); })
+
+(define_expand "extendtftd2_vr"
+  [(match_operand:TD 0 "nonimmediate_operand" "")
+   (match_operand:TF 1 "nonimmediate_operand" "")]
+  "TARGET_HARD_DFP && TARGET_VXE"
+{
+  rtx fprx2 = gen_reg_rtx (FPRX2mode);
+  emit_insn (gen_tf_to_fprx2 (fprx2, operands[1]));
+  emit_insn (gen_extendfprx2td2 (operands[0], fprx2));
+  DONE;
+})
+
+(define_expand "extendtftd2"
+  [(match_operand:TD 0 "nonimmediate_operand" "")
+   (match_operand:TF 1 "nonimmediate_operand" "")]
+  "HAVE_TF (extendtftd2)"
+  { EXPAND_TF (extendtftd2, 2); })
+
 ; test data class
 
 (define_expand "signbittf2_vr"

gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal128.c

@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+#include <stdint.h>
+
+__attribute__ ((noipa)) static long double
+long_double_from_decimal128 (_Decimal128 x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_from_decimal128 ((_Decimal128) 42) == 42.L);
+  assert (long_double_from_decimal128 ((_Decimal128) -42) == -42.L);
+}

gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal32.c

@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+#include <stdint.h>
+
+__attribute__ ((noipa)) static long double
+long_double_from_decimal32 (_Decimal32 x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_from_decimal32 ((_Decimal32) 42) == 42.L);
+  assert (long_double_from_decimal32 ((_Decimal32) -42) == -42.L);
+}

gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal64.c

@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+#include <stdint.h>
+
+__attribute__ ((noipa)) static long double
+long_double_from_decimal64 (_Decimal64 x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_from_decimal64 ((_Decimal64) 42) == 42.L);
+  assert (long_double_from_decimal64 ((_Decimal64) -42) == -42.L);
+}

gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal128.c

@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+
+__attribute__ ((noipa)) static _Decimal128
+long_double_to_decimal128 (long double x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_to_decimal128 (42.L) == (_Decimal128) 42.);
+  assert (long_double_to_decimal128 (-42.L) == (_Decimal128) -42.);
+}

gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal32.c

@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+
+__attribute__ ((noipa)) static _Decimal32
+long_double_to_decimal32 (long double x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_to_decimal32 (42.L) == (_Decimal32) 42.);
+  assert (long_double_to_decimal32 (-42.L) == (_Decimal32) -42.);
+}

gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal64.c

@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
+/* { dg-do run { target { s390_z14_hw } } } */
+#include <assert.h>
+
+__attribute__ ((noipa)) static _Decimal64
+long_double_to_decimal64 (long double x)
+{
+  return x;
+}
+
+/* { dg-final { scan-assembler-times {\n\tpfpo\n} 1 } } */
+
+int
+main (void)
+{
+  assert (long_double_to_decimal64 (42.L) == (_Decimal64) 42.);
+  assert (long_double_to_decimal64 (-42.L) == (_Decimal64) -42.);
+}