[PATCH 1/4] libiberty: Add fp8 float formats

[<Ezra.Sitorus@arm.com>]

From: Ezra Sitorus <ezra.sitorus@arm.com>

Add the 8 bit floating point formats E5M2 and E4M3 to libiberty.

E5M2 follows the IEEE convention on special values while E4M3 increases
the dynamic range by reducing the number of values. Note that this patch
only adds the values required for struct floatformat - another patch is
sent in gdb to determine the output of these values.

Technical information on FP8 can be found here:
https://arxiv.org/abs/2209.05433

The gcc patch is here: https://sourceware.org/pipermail/gcc-patches/2025-September/696165.html
---
 libiberty/floatformat.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c
index fe82e019cc9..96ab956aef0 100644
--- a/libiberty/floatformat.c
+++ b/libiberty/floatformat.c
@@ -269,6 +269,38 @@ const struct floatformat floatformat_arm_ext_littlebyte_bigword =
   floatformat_always_valid,
   NULL
 };
+const struct floatformat floatformat_fp8_e5m2_big =
+{
+  floatformat_big, 8, 0, 1, 5, 15, 31, 6, 2,
+  floatformat_intbit_no,
+  "floatformat_fp8_e5m2_big",
+  floatformat_always_valid,
+  NULL
+};
+const struct floatformat floatformat_fp8_e5m2_little =
+{
+  floatformat_little, 8, 0, 1, 5, 15, 31, 6, 2,
+  floatformat_intbit_no,
+  "floatformat_fp8_e5m2_little",
+  floatformat_always_valid,
+  NULL
+};
+const struct floatformat floatformat_fp8_e4m3_big =
+{
+  floatformat_big, 8, 0, 1, 4, 7, 15, 5, 3,
+  floatformat_intbit_no,
+  "floatformat_fp8_e4m3_big",
+  floatformat_always_valid,
+  NULL
+};
+const struct floatformat floatformat_fp8_e4m3_little =
+{
+  floatformat_little, 8, 0, 1, 4, 7, 15, 5, 3,
+  floatformat_intbit_no,
+  "floatformat_fp8_e4m3_little",
+  floatformat_always_valid,
+  NULL
+};
 const struct floatformat floatformat_ia64_spill_big =
 {
   floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
-- 
2.45.2