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.

7 files changed, 189 insertions, 0 deletions

diff --git a/gcc/config/s390/vector.md b/gcc/config/s390/vector.md
index e48c965..bc52211 100644
--- a/gcc/config/s390/vector.md
+++ b/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"
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal128.c b/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal128.c
new file mode 100644
index 0000000..3cd2c68
--- /dev/null
+++ b/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);
+}
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal32.c b/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal32.c
new file mode 100644
index 0000000..84e3c4b
--- /dev/null
+++ b/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);
+}
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal64.c b/gcc/testsuite/gcc.target/s390/vector/long-double-from-decimal64.c
new file mode 100644
index 0000000..f855e4b
--- /dev/null
+++ b/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);
+}
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal128.c b/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal128.c
new file mode 100644
index 0000000..5f7833a
--- /dev/null
+++ b/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.);
+}
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal32.c b/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal32.c
new file mode 100644
index 0000000..f09288a
--- /dev/null
+++ b/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.);
+}
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal64.c b/gcc/testsuite/gcc.target/s390/vector/long-double-to-decimal64.c
new file mode 100644
index 0000000..08aecfe
--- /dev/null
+++ b/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.);
+}