As per architecture, SuperH has a reversed NaN signalling bit
vs IEEE754-2008, it also has a NaN propgation rule similar to
MIPS style.
Use mips style float format and mode for all float types, and
correct sfp-machine header accordingly.
PR target/111814
gcc/ChangeLog:
* config/sh/sh-modes.def (RESET_FLOAT_FORMAT): Use mips format.
(FLOAT_MODE): Use mips mode.
libgcc/ChangeLog:
* config/sh/sfp-machine.h (_FP_NANFRAC_B): Reverse signaling bit.
(_FP_NANFRAC_H): Likewise.
(_FP_NANFRAC_S): Likewise.
(_FP_NANFRAC_D): Likewise.
(_FP_NANFRAC_Q): Likewise.
(_FP_KEEPNANFRACP): Enable for target.
(_FP_QNANNEGATEDP): Enable for target.
(_FP_CHOOSENAN): Port from MIPS.
gcc/testsuite/ChangeLog:
* gcc.target/sh/pr111814.c: New test.
Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
Changes in v2:
- Fix compile error
- Link to v1:
https://inbox.sourceware.org/20241231-sh-nan-v1-1-6ee9c9130...@flygoat.com
---
gcc/config/sh/sh-modes.def | 6 ++++++
gcc/testsuite/gcc.target/sh/pr111814.c | 7 +++++++
libgcc/config/sh/sfp-machine.h | 36 ++++++++++++++++++++++------------
3 files changed, 36 insertions(+), 13 deletions(-)
diff --git a/gcc/config/sh/sh-modes.def b/gcc/config/sh/sh-modes.def
index
a1d6fa9c4903abefa5b3be664853542e41f53a78..b5b459b8da60a8ad8e61a38bf4c437e8a100aa97
100644
--- a/gcc/config/sh/sh-modes.def
+++ b/gcc/config/sh/sh-modes.def
@@ -17,6 +17,12 @@ You should have received a copy of the GNU General Public
License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
+/* SH has the same reversed quiet bit as MIPS. */
+RESET_FLOAT_FORMAT (SF, mips_single_format);
+RESET_FLOAT_FORMAT (DF, mips_double_format);
+/* TFmode: IEEE quad floating point (software). */
+FLOAT_MODE (TF, 16, mips_quad_format);
+
/* Vector modes. */
VECTOR_MODE (INT, QI, 2); /* V2QI */
VECTOR_MODES (INT, 4); /* V4QI V2HI */
diff --git a/gcc/testsuite/gcc.target/sh/pr111814.c
b/gcc/testsuite/gcc.target/sh/pr111814.c
new file mode 100644
index
0000000000000000000000000000000000000000..a88e5d786ba0c4d629d345db527c3da7ddfed0df
--- /dev/null
+++ b/gcc/testsuite/gcc.target/sh/pr111814.c
@@ -0,0 +1,7 @@
+/* Verify that __builtin_nan("") produces a constant matches
+ architecture specification. */
+/* { dg-do compile } */
+
+double d = __builtin_nan ("");
+
+/* { dg-final { scan-assembler "\t.long\t-1\n\t.long\t2146959359\n" } } */
diff --git a/libgcc/config/sh/sfp-machine.h b/libgcc/config/sh/sfp-machine.h
index
26f65166976b2a8dc5d93f69b2c7136a3e010d8e..68695cc30f941f0738016da4f7d825808b57d24b
100644
--- a/libgcc/config/sh/sfp-machine.h
+++ b/libgcc/config/sh/sfp-machine.h
@@ -39,11 +39,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.
If not, see
#define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_2_udiv(D,R,X,Y)
#define _FP_DIV_MEAT_Q(R,X,Y) _FP_DIV_MEAT_4_udiv(Q,R,X,Y)
-#define _FP_NANFRAC_B _FP_QNANBIT_B
-#define _FP_NANFRAC_H _FP_QNANBIT_H
-#define _FP_NANFRAC_S _FP_QNANBIT_S
-#define _FP_NANFRAC_D _FP_QNANBIT_D, 0
-#define _FP_NANFRAC_Q _FP_QNANBIT_Q, 0, 0, 0
+#define _FP_NANFRAC_B (_FP_QNANBIT_B - 1)
+#define _FP_NANFRAC_H (_FP_QNANBIT_H - 1)
+#define _FP_NANFRAC_S (_FP_QNANBIT_S - 1)
+#define _FP_NANFRAC_D (_FP_QNANBIT_D - 1), -1
+#define _FP_NANFRAC_Q (_FP_QNANBIT_Q - 1), -1, -1, -1
/* The type of the result of a floating point comparison. This must
match __libgcc_cmp_return__ in GCC for the target. */
@@ -56,14 +56,24 @@ typedef int __gcc_CMPtype __attribute__ ((mode
(__libgcc_cmp_return__)));
#define _FP_NANSIGN_D 0
#define _FP_NANSIGN_Q 0
-#define _FP_KEEPNANFRACP 0
-#define _FP_QNANNEGATEDP 0
-
-#define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \
- do { \
- R##_s = _FP_NANSIGN_##fs; \
- _FP_FRAC_SET_##wc(R,_FP_NANFRAC_##fs); \
- R##_c = FP_CLS_NAN; \
+#define _FP_KEEPNANFRACP 1
+#define _FP_QNANNEGATEDP 1
+
+/* X is chosen unless one of the NaNs is sNaN. */
+# define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \
+ do { \
+ if ((_FP_FRAC_HIGH_RAW_##fs(X) | \
+ _FP_FRAC_HIGH_RAW_##fs(Y)) & _FP_QNANBIT_##fs) \
+ { \
+ R##_s = _FP_NANSIGN_##fs; \
+ _FP_FRAC_SET_##wc(R,_FP_NANFRAC_##fs); \
+ } \
+ else \
+ { \
+ R##_s = X##_s; \
+ _FP_FRAC_COPY_##wc(R,X); \
+ } \
+ R##_c = FP_CLS_NAN; \
} while (0)
#define _FP_TININESS_AFTER_ROUNDING 1
---
base-commit: 3672194ad2b594027311789bab9c067b7791fabd
change-id: 20241231-sh-nan-b777b3af0342
prerequisite-change-id: 20241231-b4-workflow-2ca134652c07:v1
Best regards,
--
Jiaxun Yang <jiaxun.y...@flygoat.com>
