From: Tom Tromey <tromey@adacore.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tromey@adacore.com>
Subject: [PATCH] Handle half-float in 'x' command
Date: Fri, 24 Feb 2023 09:38:34 -0700 [thread overview]
Message-ID: <20230224163834.2675084-1-tromey@adacore.com> (raw)
Using 'x/hf' should print bytes as float16, but instead it currently
prints as an integer. I tracked this down to a missing case in
float_type_from_length.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30161
---
gdb/printcmd.c | 4 +++-
gdb/testsuite/gdb.dwarf2/dw2-bfloat16.c | 26 +++++++++++++++++++++++
gdb/testsuite/gdb.dwarf2/dw2-bfloat16.exp | 19 ++++++++++++++++-
3 files changed, 47 insertions(+), 2 deletions(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/dw2-bfloat16.c
diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index 0d3bc292d4e..6fd69818db9 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -349,7 +349,9 @@ float_type_from_length (struct type *type)
struct gdbarch *gdbarch = type->arch ();
const struct builtin_type *builtin = builtin_type (gdbarch);
- if (type->length () == builtin->builtin_float->length ())
+ if (type->length () == builtin->builtin_half->length ())
+ type = builtin->builtin_half;
+ else if (type->length () == builtin->builtin_float->length ())
type = builtin->builtin_float;
else if (type->length () == builtin->builtin_double->length ())
type = builtin->builtin_double;
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.c b/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.c
new file mode 100644
index 00000000000..30dcd38bf06
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.c
@@ -0,0 +1,26 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2023 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Storage for the 'x' test. */
+unsigned char storage[2];
+
+int
+main()
+{
+ asm ("main_label: .globl main_label");
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.exp b/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.exp
index 79058cafe7f..242d1197103 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-bfloat16.exp
@@ -21,7 +21,7 @@ load_lib dwarf.exp
# This test can only be run on targets which support DWARF-2 and use gas.
require dwarf2_support
-standard_testfile main.c -dw.S
+standard_testfile .c -dw.S
# Make some DWARF for the test.
# 0x4049 is the equivalent of 3.141 for bfloat16.
@@ -78,3 +78,20 @@ if ![runto_main] {
# Make sure we can print both types correctly.
gdb_test "print bf16_1" " = 3.141"
gdb_test "print fp16_1" " = 3.1406"
+
+set bytes {0x48 0x42}
+set endian [get_endianness]
+if {$endian == "big"} {
+ set bytes [lreverse $bytes]
+}
+
+gdb_test_no_output "set var \$s = (unsigned char *) &storage" \
+ "set convenience variable"
+gdb_test "print/x \$s\[0\] = [lindex $bytes 0]" \
+ " = $hex" "set first element"
+gdb_test "print/x \$s\[1\] = [lindex $bytes 1]" \
+ " = $hex" "set second element"
+gdb_test "print *(__fp16 *) \$s" " = 3\\.1406" \
+ "print float16 value"
+gdb_test "x/hf \$s" "$hex <storage>:\[ \t\]*3\\.1406" \
+ "examine float16 value"
--
2.39.1
next reply other threads:[~2023-02-24 16:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-24 16:38 Tom Tromey [this message]
2023-03-02 2:21 ` Simon Marchi
2023-03-02 15:50 ` Tom Tromey
2023-03-02 15:50 ` Tom Tromey
2023-03-02 21:00 ` Simon Marchi
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