| Message ID | 5661BACA.50909@gmail.com |
|---|---|
| State | New |
| Headers | show |
* Ruslan Kabatsayev <b7.10110111@gmail.com> [2015-12-04 19:09:46 +0300]: > When `info float` is used on an AMD64 system, GDB prints floating-point > values of x87 registers with raw contents like 0x361a867a8e0527397ce0 or > 0xc4f988454a1ddd3cfdab wrongly. This happens due to truncation to double, > after which the former becomes 0.0, and the latter becomes negative infinity. > This is caused by failed detection of x86-64 host, which results in setting > gdb_host_{float,double,long_double}_format to zeros. > This commit fixes this misdetection, and adds a test to make sure future > commits don't introduce a regression here. > > gdb/ChangeLog: > > * configure.host: Fix detection of x86_64 host when setting > floatformats. > * testsuite/gdb.arch/i386-float.S: Add a regression test for the fix. > * testsuite/gdb.arch/i386-float.exp: Add checking of the test results. There's a separate ChangeLog in the gdb/testsuite directory, so you need to split your entry over these two files. And remember files names in the testsuite ChangeLog don't need to have the testsuite/ prefix. Thanks, Andrew
On 12/06/2015 01:41 AM, Andrew Burgess wrote: > * Ruslan Kabatsayev <b7.10110111@gmail.com> [2015-12-04 19:09:46 +0300]: > >> When `info float` is used on an AMD64 system, GDB prints floating-point >> values of x87 registers with raw contents like 0x361a867a8e0527397ce0 or >> 0xc4f988454a1ddd3cfdab wrongly. This happens due to truncation to double, >> after which the former becomes 0.0, and the latter becomes negative infinity. >> This is caused by failed detection of x86-64 host, which results in setting >> gdb_host_{float,double,long_double}_format to zeros. >> This commit fixes this misdetection, and adds a test to make sure future >> commits don't introduce a regression here. >> >> gdb/ChangeLog: >> >> * configure.host: Fix detection of x86_64 host when setting >> floatformats. >> * testsuite/gdb.arch/i386-float.S: Add a regression test for the fix. >> * testsuite/gdb.arch/i386-float.exp: Add checking of the test results. > > There's a separate ChangeLog in the gdb/testsuite directory, so you > need to split your entry over these two files. And remember files > names in the testsuite ChangeLog don't need to have the testsuite/ > prefix. gdb/ChangeLog: * configure.host: Fix detection of x86_64 host when setting floatformats. gdb/testsuite/ChangeLog: * gdb.arch/i386-float.S: Add a regression test for the fix of floatformats setup on x86_64 hosts. * gdb.arch/i386-float.exp: Add checking of the test results for floatformats setup on x86_64 hosts. > > Thanks, > Andrew > >
diff --git a/gdb/configure.host b/gdb/configure.host index 48714f4..ef265eb 100644 --- a/gdb/configure.host +++ b/gdb/configure.host @@ -195,7 +195,7 @@ esac # "double" and "long double" types. case "${host}" in -i[34567]86-*-*) +i[34567]86-*-*|x86_64-*-*) gdb_host_float_format="&floatformat_ieee_single_little" gdb_host_double_format="&floatformat_ieee_double_little" gdb_host_long_double_format="&floatformat_i387_ext" diff --git a/gdb/testsuite/gdb.arch/i386-float.S b/gdb/testsuite/gdb.arch/i386-float.S index 76126c4..f5de8c2 100644 --- a/gdb/testsuite/gdb.arch/i386-float.S +++ b/gdb/testsuite/gdb.arch/i386-float.S @@ -29,6 +29,10 @@ SYMBOL(main): fninit fldt val + fldt bigval + fldt smallval ret .data val: .byte 0x00,0x00,0x45,0x07,0x11,0x19,0x22,0xe9,0xfe,0xbf + smallval: .byte 0xe9,0xd0,0xd7,0x65,0x81,0xb7,0x43,0xc6,0x5c,0x6a + bigval: .byte 0x6a,0x45,0x90,0xdc,0x03,0xc1,0xf8,0xc6,0xe5,0x03 diff --git a/gdb/testsuite/gdb.arch/i386-float.exp b/gdb/testsuite/gdb.arch/i386-float.exp index e638ceb..4260f29 100644 --- a/gdb/testsuite/gdb.arch/i386-float.exp +++ b/gdb/testsuite/gdb.arch/i386-float.exp @@ -39,5 +39,9 @@ if ![runto_main] then { gdb_test "stepi" ".*fldt.*" "first stepi" gdb_test "info float" ".*R7: Empty 0x00000000000000000000\r\n.*" -gdb_test "stepi" ".*ret.*" "second stepi" +gdb_test "stepi" ".*fldt.*" "second stepi" gdb_test "info float" ".*=>R7: Valid 0xbffee922191107450000 .*" +gdb_test "stepi" ".*fldt.*" "third stepi" +gdb_test "info float" ".*=>R6: Valid 0x03e5c6f8c103dc90456a \\+3.500000000000000007e-4632\r\n.*" +gdb_test "stepi" ".*ret.*" "fourth stepi" +gdb_test "info float" ".*=>R5: Valid 0x6a5cc643b78165d7d0e9 \\+7.250000000000000005e\\+3264\r\n.*"
When `info float` is used on an AMD64 system, GDB prints floating-point values of x87 registers with raw contents like 0x361a867a8e0527397ce0 or 0xc4f988454a1ddd3cfdab wrongly. This happens due to truncation to double, after which the former becomes 0.0, and the latter becomes negative infinity. This is caused by failed detection of x86-64 host, which results in setting gdb_host_{float,double,long_double}_format to zeros. This commit fixes this misdetection, and adds a test to make sure future commits don't introduce a regression here. gdb/ChangeLog: * configure.host: Fix detection of x86_64 host when setting floatformats. * testsuite/gdb.arch/i386-float.S: Add a regression test for the fix. * testsuite/gdb.arch/i386-float.exp: Add checking of the test results. --- gdb/configure.host | 2 +- gdb/testsuite/gdb.arch/i386-float.S | 4 ++++ gdb/testsuite/gdb.arch/i386-float.exp | 6 +++++- 3 files changed, 10 insertions(+), 2 deletions(-)