From b593e3d9b00b09af43abf1e95d68e68200e3c2a5 Mon Sep 17 00:00:00 2001 From: Ruslan Kabatsayev Date: Wed, 9 Dec 2015 12:17:40 +0000 Subject: [PATCH] Fix wrong output of x87 registers due to truncation to double on amd64 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: 2015-12-09 Ruslan Kabatsayev PR gdb/18702 * configure.host: Fix detection of x86_64 host when setting floatformats. gdb/testsuite/ChangeLog: 2015-12-09 Ruslan Kabatsayev Pedro Alves PR gdb/18702 Add checking of floatformats setup on x86_64 hosts. * gdb.arch/i386-float.S (main): Load bigval and smallval. (smallval, bigval): New labels/constants. * gdb.arch/i386-float.exp: Use with_test_prefix and test "info float" after loading bigval and smallval. --- gdb/ChangeLog | 6 ++++++ gdb/configure.host | 2 +- gdb/testsuite/ChangeLog | 10 ++++++++++ gdb/testsuite/gdb.arch/i386-float.S | 4 ++++ gdb/testsuite/gdb.arch/i386-float.exp | 20 ++++++++++++++++---- 5 files changed, 37 insertions(+), 5 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b5d2431dde..8a8202cebb 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2015-12-09 Ruslan Kabatsayev (tiny patch) + + PR gdb/18702 + * configure.host: Fix detection of x86_64 host when setting + floatformats. + 2015-12-08 Pierre-Marie de Rodat * NEWS: Announce this enhancement and the corresponding new diff --git a/gdb/configure.host b/gdb/configure.host index 48714f48c5..ef265ebe29 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/ChangeLog b/gdb/testsuite/ChangeLog index 8316d32773..d959e7b615 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,13 @@ +2015-12-09 Ruslan Kabatsayev + Pedro Alves + + PR gdb/18702 + Add checking of floatformats setup on x86_64 hosts. + * gdb.arch/i386-float.S (main): Load bigval and smallval. + (smallval, bigval): New labels/constants. + * gdb.arch/i386-float.exp: Use with_test_prefix and test "info + float" after loading bigval and smallval. + 2015-12-07 Pierre-Marie de Rodat * gdb.ada/fun_overload_menu.exp: New testcase. diff --git a/gdb/testsuite/gdb.arch/i386-float.S b/gdb/testsuite/gdb.arch/i386-float.S index 76126c49b6..f5de8c2ab9 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 e638cebc02..e3ae3ba6ad 100644 --- a/gdb/testsuite/gdb.arch/i386-float.exp +++ b/gdb/testsuite/gdb.arch/i386-float.exp @@ -37,7 +37,19 @@ if ![runto_main] then { return 0 } -gdb_test "stepi" ".*fldt.*" "first stepi" -gdb_test "info float" ".*R7: Empty 0x00000000000000000000\r\n.*" -gdb_test "stepi" ".*ret.*" "second stepi" -gdb_test "info float" ".*=>R7: Valid 0xbffee922191107450000 .*" +with_test_prefix "zero" { + gdb_test "stepi" ".*fldt.*" + gdb_test "info float" "R7: Empty 0x00000000000000000000\r\n.*" +} +with_test_prefix "val" { + gdb_test "stepi" ".*fldt.*" + gdb_test "info float" "=>R7: Valid 0xbffee922191107450000 .*" +} +with_test_prefix "smallval" { + gdb_test "stepi" ".*fldt.*" + gdb_test "info float" "=>R6: Valid 0x03e5c6f8c103dc90456a \\+3.500000000000000007e-4632\r\n.*" +} +with_test_prefix "bigval" { + gdb_test "stepi" ".*ret.*" + gdb_test "info float" "=>R5: Valid 0x6a5cc643b78165d7d0e9 \\+7.250000000000000005e\\+3264\r\n.*" +} -- 2.34.1