libgcc: Rename __trunchfbf2 to __extendhfbf2
Checks
Context |
Check |
Description |
linaro-tcwg-bot/tcwg_gcc_build--master-arm |
success
|
Testing passed
|
linaro-tcwg-bot/tcwg_gcc_build--master-aarch64 |
success
|
Testing passed
|
linaro-tcwg-bot/tcwg_gcc_check--master-arm |
success
|
Testing passed
|
linaro-tcwg-bot/tcwg_gcc_check--master-aarch64 |
success
|
Testing passed
|
Commit Message
Since bfloat16 has the same range as float32, _Float16 to bfloat16
conversion is an extension, not a truncation. Rename trunchfbf2.c
to extendhfbf2.c to provide __extendhfbf2, instead of __trunchfbf2.
Since _Float16 to bfloat16 conversion never worked from the day one,
the same libgcc version of __trunchfbf2 is used with __extendhfbf2 so
that this can be backported to release branches all the way where
__trunchfbf2 was added.
gcc/testsuite/
PR libgcc/114907
* gcc.dg/pr114907-1.c: New test.
* gcc.dg/pr114907-2.c: Likewise.
libgcc/
PR libgcc/114907
* config/aarch64/libgcc-softfp.ver (__trunchfbf2): Renamed to ...
(__extendhfbf2): This.
* config/aarch64/t-softfp (softfp_extensions): Add hfbf.
(softfp_truncations): Remove hfbf.
* config/i386/libgcc-darwin.ver (__trunchfbf2): Renamed to ...
(__extendhfbf2): This.
* config/i386/libgcc-glibc.ver (__trunchfbf2): Renamed to ...
(__extendhfbf2): This.
* config/i386/libgcc-sol2.ver (__trunchfbf2): Renamed to ...
(__extendhfbf2): This.
* config/i386/t-softfp (softfp_extensions): Add hfbf.
(softfp_truncations): Remove hfbf.
(CFLAGS-trunchfbf2.c): Renamed to ...
(CFLAGS-extendhfbf2.c): This.
* soft-fp/trunchfbf2.c: Renamed to ...
* soft-fp/extendhfbf2.c: This.
(__trunchfbf2): Renamed to ...
(__extendhfbf2): This.
---
gcc/testsuite/gcc.dg/pr114907-1.c | 21 +++++++++++++++++++
gcc/testsuite/gcc.dg/pr114907-2.c | 17 +++++++++++++++
libgcc/config/aarch64/libgcc-softfp.ver | 2 +-
libgcc/config/aarch64/t-softfp | 4 ++--
libgcc/config/i386/libgcc-darwin.ver | 2 +-
libgcc/config/i386/libgcc-glibc.ver | 2 +-
libgcc/config/i386/libgcc-sol2.ver | 2 +-
libgcc/config/i386/t-softfp | 6 +++---
.../soft-fp/{trunchfbf2.c => extendhfbf2.c} | 6 +++---
9 files changed, 50 insertions(+), 12 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr114907-1.c
create mode 100644 gcc/testsuite/gcc.dg/pr114907-2.c
rename libgcc/soft-fp/{trunchfbf2.c => extendhfbf2.c} (94%)
Comments
On Wed, May 01, 2024 at 12:55:25PM -0700, H.J. Lu wrote:
> Since bfloat16 has the same range as float32, _Float16 to bfloat16
> conversion is an extension, not a truncation. Rename trunchfbf2.c
> to extendhfbf2.c to provide __extendhfbf2, instead of __trunchfbf2.
>
> Since _Float16 to bfloat16 conversion never worked from the day one,
> the same libgcc version of __trunchfbf2 is used with __extendhfbf2 so
> that this can be backported to release branches all the way where
> __trunchfbf2 was added.
This is wrong.
First of all, it is ABI incompatible change, we can't do that.
And second, neither _Float16 is a subset of __bf16 nor the other way,
so both extend and trunc names are equally wrong.
Jakub
new file mode 100644
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+/* { dg-options "-O0" } */
+/* { dg-add-options bfloat16 } */
+/* { dg-require-effective-target bfloat16_runtime } */
+
+__bf16 bfa, bfb, bfc, bfd, bfe, bff;
+_Float16 f16a, f16b;
+float f32a, f32b;
+double da, db;
+
+int
+main (void)
+{
+ bfa = f16a;
+ f16b = bfb;
+ bfc = f32a;
+ f32b = bfd;
+ bfe = da;
+ db = bff;
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,17 @@
+/* { dg-do run } */
+/* { dg-options "-O0" } */
+/* { dg-add-options bfloat16 } */
+/* { dg-add-options __float128 } */
+/* { dg-require-effective-target bfloat16_runtime } */
+/* { dg-require-effective-target __float128 } */
+
+__bf16 bfa, bfb;
+__float128 fa, fb;
+
+int
+main (void)
+{
+ bfa = fa;
+ fb = bfb;
+ return 0;
+}
@@ -30,6 +30,7 @@ GCC_11.0 {
%inherit GCC_13.0.0 GCC_11.0.0
GCC_13.0.0 {
__extendbfsf2
+ __extendhfbf2
__floatdibf
__floattibf
__floatundibf
@@ -37,7 +38,6 @@ GCC_13.0.0 {
__truncdfbf2
__truncsfbf2
__trunctfbf2
- __trunchfbf2
}
%inherit GCC_14.0.0 GCC_13.0.0
@@ -1,7 +1,7 @@
softfp_float_modes := tf
softfp_int_modes := si di ti
-softfp_extensions := sftf dftf hftf bfsf
-softfp_truncations := tfsf tfdf tfhf tfbf dfbf sfbf hfbf
+softfp_extensions := sftf dftf hftf bfsf hfbf
+softfp_truncations := tfsf tfdf tfhf tfbf dfbf sfbf
softfp_exclude_libgcc2 := n
softfp_extras += fixhfti fixunshfti floattihf floatuntihf \
floatdibf floatundibf floattibf floatuntibf \
@@ -29,13 +29,13 @@ GCC_12.0.0 {
GCC_14.0.0 {
# Added to GCC_13.0.0 in i386/libgcc-glibc.ver.
__extendbfsf2
+ __extendhfbf2
__floattibf
__floatuntibf
__truncdfbf2
__truncsfbf2
__trunctfbf2
__truncxfbf2
- __trunchfbf2
# Added to GCC_14.0.0 in i386/libgcc-glibc.ver.
__fixxfbitint
__fixtfbitint
@@ -218,13 +218,13 @@ GCC_12.0.0 {
%inherit GCC_13.0.0 GCC_12.0.0
GCC_13.0.0 {
__extendbfsf2
+ __extendhfbf2
__floattibf
__floatuntibf
__truncdfbf2
__truncsfbf2
__trunctfbf2
__truncxfbf2
- __trunchfbf2
}
%inherit GCC_14.0.0 GCC_13.0.0
@@ -136,13 +136,13 @@ GCC_14.0.0 {
__truncxfhf2
# Added to GCC_13.0.0 in i386/libgcc-glibc.ver.
__extendbfsf2
+ __extendhfbf2
__floattibf
__floatuntibf
__truncdfbf2
__truncsfbf2
__trunctfbf2
__truncxfbf2
- __trunchfbf2
# Added to GCC_14.0.0 in i386/libgcc-glibc.ver.
__fixxfbitint
__fixtfbitint
@@ -6,9 +6,9 @@ LIB2FUNCS_EXCLUDE += $(libgcc2-hf-functions)
libgcc2-hf-extras = $(addsuffix .c, $(libgcc2-hf-functions))
LIB2ADD += $(addprefix $(srcdir)/config/i386/, $(libgcc2-hf-extras))
-softfp_extensions := hfsf hfdf hftf hfxf sfdf sftf dftf xftf bfsf
+softfp_extensions := hfsf hfdf hftf hfxf sfdf sftf dftf xftf bfsf hfbf
softfp_truncations := tfhf xfhf dfhf sfhf tfsf dfsf tfdf tfxf \
- tfbf xfbf dfbf sfbf hfbf
+ tfbf xfbf dfbf sfbf
softfp_extras += eqhf2 fixxfbitint $(foreach m,hf bf xf,floatbitint$(m))
@@ -17,6 +17,7 @@ CFLAGS-extendhfdf2.c += -msse2
CFLAGS-extendhftf2.c += -msse2
CFLAGS-extendhfxf2.c += -msse2
CFLAGS-extendbfsf2.c += -msse2
+CFLAGS-extendhfbf2.c += -msse2
CFLAGS-truncsfhf2.c += -msse2
CFLAGS-truncdfhf2.c += -msse2
@@ -26,7 +27,6 @@ CFLAGS-truncsfbf2.c += -msse2
CFLAGS-truncdfbf2.c += -msse2
CFLAGS-truncxfbf2.c += -msse2
CFLAGS-trunctfbf2.c += -msse2
-CFLAGS-trunchfbf2.c += -msse2
CFLAGS-floatbitintbf.c += -msse2
CFLAGS-floatbitinthf.c += -msse2
similarity index 94%
rename from libgcc/soft-fp/trunchfbf2.c
rename to libgcc/soft-fp/extendhfbf2.c
@@ -1,6 +1,6 @@
/* Software floating-point emulation.
- Truncate IEEE half into bfloat16.
- Copyright (C) 2022 Free Software Foundation, Inc.
+ Extend IEEE half into bfloat16.
+ Copyright (C) 2022-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -36,7 +36,7 @@
truncate to BFtype. */
BFtype
-__trunchfbf2 (HFtype a)
+__extendhfbf2 (HFtype a)
{
FP_DECL_EX;
FP_DECL_H (A);