diff options
| -rw-r--r-- | ChangeLog | 3 | ||||
| -rw-r--r-- | generic/tclExecute.c | 79 | ||||
| -rw-r--r-- | tests/expr.test | 12 |
3 files changed, 86 insertions, 8 deletions
@@ -1,5 +1,8 @@ 2004-09-18 Donal K. Fellows <donal.k.fellows@man.ac.uk> + * generic/tclExecute.c (TEBC-INST_LSHIFT,INST_RSHIFT): Ensure that + large shifts end up shifting correctly. [Bug 868467] + * doc/FileSystem.3, doc/OpenFileChnl.3: More documentation fixes from Mikhail Kolesnitchenko. [Patch 1022527] * doc/*: Standardize highlighting of symbols defined in tcl.h diff --git a/generic/tclExecute.c b/generic/tclExecute.c index b965944..a5dd499 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -11,7 +11,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclExecute.c,v 1.147 2004/09/11 13:45:15 msofer Exp $ + * RCS: @(#) $Id: tclExecute.c,v 1.148 2004/09/18 18:04:04 dkf Exp $ */ #ifdef STDC_HEADERS @@ -3600,11 +3600,42 @@ TclExecuteByteCode(interp, codePtr) #ifdef TCL_COMPILE_DEBUG w2 = Tcl_LongAsWide(i2); #endif /* TCL_COMPILE_DEBUG */ - wResult = w << i2; + wResult = w; + /* + * Shift in steps when the shift gets large to prevent + * annoying compiler/processor bugs. [Bug 868467] + */ + if (i2 >= 64) { + wResult = Tcl_LongAsWide(0); + } else if (i2 > 60) { + wResult = w << 30; + wResult <<= 30; + wResult <<= i2-60; + } else if (i2 > 30) { + wResult = w << 30; + wResult <<= i2-30; + } else { + wResult = w << i2; + } doWide = 1; break; } - iResult = i << i2; + /* + * Shift in steps when the shift gets large to prevent + * annoying compiler/processor bugs. [Bug 868467] + */ + if (i2 >= 64) { + iResult = 0; + } else if (i2 > 60) { + iResult = i << 30; + iResult <<= 30; + iResult <<= i2-60; + } else if (i2 > 30) { + iResult = i << 30; + iResult <<= i2-30; + } else { + iResult = i << i2; + } break; case INST_RSHIFT: /* @@ -3621,17 +3652,51 @@ TclExecuteByteCode(interp, codePtr) w2 = Tcl_LongAsWide(i2); #endif /* TCL_COMPILE_DEBUG */ if (w < 0) { - wResult = ~((~w) >> i2); + wResult = ~w; + } + /* + * Shift in steps when the shift gets large to prevent + * annoying compiler/processor bugs. [Bug 868467] + */ + if (i2 >= 64) { + wResult = Tcl_LongAsWide(0); + } else if (i2 > 60) { + wResult <<= 30; + wResult <<= 30; + wResult <<= i2-60; + } else if (i2 > 30) { + wResult <<= 30; + wResult <<= i2-30; } else { - wResult = w >> i2; + wResult <<= i2; + } + if (w < 0) { + wResult = ~wResult; } doWide = 1; break; } if (i < 0) { - iResult = ~((~i) >> i2); + iResult = ~i; + } + /* + * Shift in steps when the shift gets large to prevent + * annoying compiler/processor bugs. [Bug 868467] + */ + if (i2 >= 64) { + iResult = 0; + } else if (i2 > 60) { + iResult <<= 30; + iResult <<= 30; + iResult <<= i2-60; + } else if (i2 > 30) { + iResult <<= 30; + iResult <<= i2-30; } else { - iResult = i >> i2; + iResult <<= i2; + } + if (i < 0) { + iResult = ~iResult; } break; case INST_BITOR: diff --git a/tests/expr.test b/tests/expr.test index 059f7f3..028f56f 100644 --- a/tests/expr.test +++ b/tests/expr.test @@ -10,7 +10,7 @@ # See the file "license.terms" for information on usage and redistribution # of this file, and for a DISCLAIMER OF ALL WARRANTIES. # -# RCS: @(#) $Id: expr.test,v 1.22 2004/06/23 15:36:56 dkf Exp $ +# RCS: @(#) $Id: expr.test,v 1.23 2004/09/18 18:04:06 dkf Exp $ if {[lsearch [namespace children] ::tcltest] == -1} { package require tcltest @@ -860,6 +860,16 @@ test epxr-23.31 {INST_EXPON: special cases} {expr {wide(-1)**wide(-1)}} -1 test epxr-23.32 {INST_EXPON: special cases} {expr {wide(1)**wide(1234567)}} 1 test epxr-23.33 {INST_EXPON: special cases} {expr {wide(2)**wide(-2)}} 0 +# Some compilers get this wrong; ensure that we work around it correctly +test expr-24.1 {expr edge cases; shifting} {expr int(5)>>32} 0 +test expr-24.2 {expr edge cases; shifting} {expr int(5)>>63} 0 +test expr-24.3 {expr edge cases; shifting} {expr wide(5)>>32} 0 +test expr-24.4 {expr edge cases; shifting} {expr wide(5)>>63} 0 +test expr-24.5 {expr edge cases; shifting} {expr int(5)<<32} 0 +test expr-24.6 {expr edge cases; shifting} {expr int(5)<<63} 0 +test expr-24.7 {expr edge cases; shifting} {expr wide(5)<<32} 0 +test expr-24.8 {expr edge cases; shifting} {expr wide(5)<<63} 0 + # cleanup if {[info exists a]} { unset a |