diff options
-rw-r--r-- | ChangeLog | 8 | ||||
-rw-r--r-- | generic/tclExecute.c | 428 | ||||
-rw-r--r-- | tests/expr.test | 124 |
3 files changed, 555 insertions, 5 deletions
@@ -1,3 +1,11 @@ +2007-08-25 Kevin B. Kenny <kennykb@acm.org> + + * generic/tclExecute.c (TclExecuteByteCode): Added code to handle + * tests/expr.test (expr-23.48-53) integer exponentiation + that results in 32- and 64-bit integer results, avoiding calls to + wide integer exponentiation routines in this common case. + [Bug 1767293] + 2007-08-24 Don Porter <dgp@users.sourceforge.net> * generic/tclCompExpr.c: Register literals found in expressions diff --git a/generic/tclExecute.c b/generic/tclExecute.c index 07de1b6..bb4c9a4 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -12,7 +12,7 @@ * 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 1.322 2007/08/22 14:31:04 msofer Exp $ + * RCS: @(#) $Id: tclExecute.c,v 1.323 2007/08/25 03:23:17 kennykb Exp $ */ #include "tclInt.h" @@ -445,6 +445,138 @@ static Tcl_ObjType dictIteratorType = { }; /* + * Auxiliary tables used to compute powers of small integers + */ + +#if (LONG_MAX == 0x7fffffff) + +/* + * Maximum base that, when raised to powers 2, 3, ... 8, fits in a 32-bit + * signed integer + */ + +static const long MaxBase32[7] = {46340, 1290, 215, 73, 35, 21, 14}; + +/* + * Table giving 3, 4, ..., 11, raised to the powers 9, 10, ..., + * as far as they fit in a 32-bit signed integer. Exp32Index[i] gives + * the starting index of powers of i+3; Exp32Value[i] gives the corresponding + * powers. + */ + +static const unsigned short Exp32Index[] = { + 0, 11, 18, 23, 26, 29, 31, 32, 33 +}; +static const long Exp32Value[] = { + 19683, 59049, 177147, 531441, 1594323, 4782969, 14348907, 43046721, + 129140163, 387420489, 1162261467, 262144, 1048576, 4194304, + 16777216, 67108864, 268435456, 1073741824, 1953125, 9765625, + 48828125, 244140625, 1220703125, 10077696, 60466176, 362797056, + 40353607, 282475249, 1977326743, 134217728, 1073741824, 387420489, + 1000000000 +}; + +#endif /* LONG_MAX == 0x7fffffff -- 32 bit machine */ + +#if (LONG_MAX > 0x7fffffff) || !defined(TCL_WIDE_INT_IS_LONG) + +/* + * Maximum base that, when raised to powers 2, 3, ..., 16, fits in a + * Tcl_WideInt. + */ + +static Tcl_WideInt MaxBaseWide[15]; + +/* + *Table giving 3, 4, ..., 13 raised to powers greater than 16 when the + * results fit in a 64-bit signed integer. + */ + +static const unsigned short Exp64Index[] = { + 0, 23, 38, 49, 57, 63, 67, 70, 72, 74, 75, 76 +}; +static const Tcl_WideInt Exp64Value[] = { + (Tcl_WideInt)243*243*243*3*3, + (Tcl_WideInt)243*243*243*3*3*3, + (Tcl_WideInt)243*243*243*3*3*3*3, + (Tcl_WideInt)243*243*243*243, + (Tcl_WideInt)243*243*243*243*3, + (Tcl_WideInt)243*243*243*243*3*3, + (Tcl_WideInt)243*243*243*243*3*3*3, + (Tcl_WideInt)243*243*243*243*3*3*3*3, + (Tcl_WideInt)243*243*243*243*243, + (Tcl_WideInt)243*243*243*243*243*3, + (Tcl_WideInt)243*243*243*243*243*3*3, + (Tcl_WideInt)243*243*243*243*243*3*3*3, + (Tcl_WideInt)243*243*243*243*243*3*3*3*3, + (Tcl_WideInt)243*243*243*243*243*243, + (Tcl_WideInt)243*243*243*243*243*243*3, + (Tcl_WideInt)243*243*243*243*243*243*3*3, + (Tcl_WideInt)243*243*243*243*243*243*3*3*3, + (Tcl_WideInt)243*243*243*243*243*243*3*3*3*3, + (Tcl_WideInt)243*243*243*243*243*243*243, + (Tcl_WideInt)243*243*243*243*243*243*243*3, + (Tcl_WideInt)243*243*243*243*243*243*243*3*3, + (Tcl_WideInt)243*243*243*243*243*243*243*3*3*3, + (Tcl_WideInt)243*243*243*243*243*243*243*3*3*3*3, + (Tcl_WideInt)1024*1024*1024*4*4, + (Tcl_WideInt)1024*1024*1024*4*4*4, + (Tcl_WideInt)1024*1024*1024*4*4*4*4, + (Tcl_WideInt)1024*1024*1024*1024, + (Tcl_WideInt)1024*1024*1024*1024*4, + (Tcl_WideInt)1024*1024*1024*1024*4*4, + (Tcl_WideInt)1024*1024*1024*1024*4*4*4, + (Tcl_WideInt)1024*1024*1024*1024*4*4*4*4, + (Tcl_WideInt)1024*1024*1024*1024*1024, + (Tcl_WideInt)1024*1024*1024*1024*1024*4, + (Tcl_WideInt)1024*1024*1024*1024*1024*4*4, + (Tcl_WideInt)1024*1024*1024*1024*1024*4*4*4, + (Tcl_WideInt)1024*1024*1024*1024*1024*4*4*4*4, + (Tcl_WideInt)1024*1024*1024*1024*1024*1024, + (Tcl_WideInt)1024*1024*1024*1024*1024*1024*4, + (Tcl_WideInt)3125*3125*3125*5*5, + (Tcl_WideInt)3125*3125*3125*5*5*5, + (Tcl_WideInt)3125*3125*3125*5*5*5*5, + (Tcl_WideInt)3125*3125*3125*3125, + (Tcl_WideInt)3125*3125*3125*3125*5, + (Tcl_WideInt)3125*3125*3125*3125*5*5, + (Tcl_WideInt)3125*3125*3125*3125*5*5*5, + (Tcl_WideInt)3125*3125*3125*3125*5*5*5*5, + (Tcl_WideInt)3125*3125*3125*3125*3125, + (Tcl_WideInt)3125*3125*3125*3125*3125*5, + (Tcl_WideInt)3125*3125*3125*3125*3125*5*5, + (Tcl_WideInt)7776*7776*7776*6*6, + (Tcl_WideInt)7776*7776*7776*6*6*6, + (Tcl_WideInt)7776*7776*7776*6*6*6*6, + (Tcl_WideInt)7776*7776*7776*7776, + (Tcl_WideInt)7776*7776*7776*7776*6, + (Tcl_WideInt)7776*7776*7776*7776*6*6, + (Tcl_WideInt)7776*7776*7776*7776*6*6*6, + (Tcl_WideInt)7776*7776*7776*7776*6*6*6*6, + (Tcl_WideInt)16807*16807*16807*7*7, + (Tcl_WideInt)16807*16807*16807*7*7*7, + (Tcl_WideInt)16807*16807*16807*7*7*7*7, + (Tcl_WideInt)16807*16807*16807*16807, + (Tcl_WideInt)16807*16807*16807*16807*7, + (Tcl_WideInt)16807*16807*16807*16807*7*7, + (Tcl_WideInt)32768*32768*32768*8*8, + (Tcl_WideInt)32768*32768*32768*8*8*8, + (Tcl_WideInt)32768*32768*32768*8*8*8*8, + (Tcl_WideInt)32768*32768*32768*32768, + (Tcl_WideInt)59049*59049*59049*9*9, + (Tcl_WideInt)59049*59049*59049*9*9*9, + (Tcl_WideInt)59049*59049*59049*9*9*9*9, + (Tcl_WideInt)100000*100000*100000*10*10, + (Tcl_WideInt)100000*100000*100000*10*10*10, + (Tcl_WideInt)161051*161051*161051*11*11, + (Tcl_WideInt)161051*161051*161051*11*11*11, + (Tcl_WideInt)248832*248832*248832*12*12, + (Tcl_WideInt)371293*371293*371293*13*13 +}; + +#endif + +/* * Declarations for local procedures to this file: */ @@ -504,6 +636,9 @@ InitByteCodeExecution( * "tcl_traceExec" is linked to control * instruction tracing. */ { +#if (LONG_MAX > 0x7fffffff) || !defined(TCL_WIDE_INT_IS_LONG) + int i; +#endif #ifdef TCL_COMPILE_DEBUG if (Tcl_LinkVar(interp, "tcl_traceExec", (char *) &tclTraceExec, TCL_LINK_INT) != TCL_OK) { @@ -514,6 +649,11 @@ InitByteCodeExecution( Tcl_CreateObjCommand(interp, "evalstats", EvalStatsCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL); #endif /* TCL_COMPILE_STATS */ +#if (LONG_MAX > 0x7fffffff) || !defined(TCL_WIDE_INT_IS_LONG) + for (i = 2; i <= 16; ++i) { + MaxBaseWide[i-2] = (Tcl_WideInt) pow((double) LLONG_MAX, 1.0 / i); + } +#endif } /* @@ -5153,7 +5293,8 @@ TclExecuteByteCode( /* TODO: Attempts to re-use unshared operands on stack */ if (*pc == INST_EXPON) { - long l1, l2 = 0; + long l1 = 0, l2 = 0; + Tcl_WideInt w1; int oddExponent = 0, negativeExponent = 0; if (type2 == TCL_NUMBER_LONG) { @@ -5165,8 +5306,14 @@ TclExecuteByteCode( objResultPtr = constants[1]; NEXT_INST_F(1, 2, 1); + } else if (l2 == 1) { + /* + * Anything to the first power is itself + */ + NEXT_INST_F(1, 1, 0); } } + switch (type2) { case TCL_NUMBER_LONG: { negativeExponent = (l2 < 0); @@ -5264,7 +5411,282 @@ TclExecuteByteCode( result = TCL_ERROR; goto checkForCatch; } - /* TODO: Perform those computations that fit in native types */ + + if (type1 == TCL_NUMBER_LONG && type2 == TCL_NUMBER_LONG) { + if (l1 == 2) { + /* + * Reduce small powers of 2 to shifts. + */ + if (l2 < CHAR_BIT * sizeof(long) - 1) { + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + TclNewLongObj(objResultPtr, (1L << l2)); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } +#if !defined(TCL_WIDE_INT_IS_LONG) + if (l2 < CHAR_BIT * sizeof(Tcl_WideInt) - 1) { + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + objResultPtr + = Tcl_NewWideIntObj(((Tcl_WideInt) 1) << l2); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } +#endif + } + if (l1 == -2) { + int signum = oddExponent ? -1 : 1; + /* + * Reduce small powers of 2 to shifts. + */ + if (l2 < CHAR_BIT * sizeof(long) - 1) { + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + TclNewLongObj(objResultPtr, signum * (1L << l2)); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } +#if !defined(TCL_WIDE_INT_IS_LONG) + if (l2 < CHAR_BIT * sizeof(Tcl_WideInt) - 1) { + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + objResultPtr + = Tcl_NewWideIntObj(signum * + (((Tcl_WideInt) 1) << l2)); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } +#endif + } +#if (LONG_MAX == 0x7fffffff) + if (l2 <= 8 && + l1 <= MaxBase32[l2-2] && l1 >= -MaxBase32[l2-2]) { + /* + * Small powers of 32-bit integers + */ + long lResult = l1 * l1; /* b**2 */ + switch (l2) { + case 2: + break; + case 3: + lResult *= l1; /* b**3 */ + break; + case 4: + lResult *= lResult; /* b**4 */ + break; + case 5: + lResult *= lResult; /* b**4 */ + lResult *= l1; /* b**5 */ + break; + case 6: + lResult *= l1; /* b**3 */ + lResult *= lResult; /* b**6 */ + break; + case 7: + lResult *= l1; /* b**3 */ + lResult *= lResult; /* b**6 */ + lResult *= l1; /* b**7 */ + break; + case 8: + lResult *= lResult; /* b**4 */ + lResult *= lResult; /* b**8 */ + break; + } + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + if (Tcl_IsShared(valuePtr)) { + TclNewLongObj(objResultPtr, lResult); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + Tcl_SetLongObj(valuePtr, lResult); + TRACE(("%s\n", O2S(valuePtr))); + NEXT_INST_F(1, 1, 0); + } + if (l1 >= 3 + && l1 < (sizeof(Exp32Index) + / sizeof(unsigned short)) - 1) { + unsigned short base = Exp32Index[l1-3] + l2 - 9; + if (base < Exp32Index[l1-2]) { + /* + * 32-bit number raised to intermediate power, + * done by table lookup + */ + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + if (Tcl_IsShared(valuePtr)) { + TclNewLongObj(objResultPtr, Exp32Value[base]); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + Tcl_SetLongObj(valuePtr, Exp32Value[base]); + TRACE(("%s\n", O2S(valuePtr))); + NEXT_INST_F(1, 1, 0); + } + } + if (-l1 >= 3 + && -l1 < (sizeof(Exp32Index) + / sizeof(unsigned short)) - 1) { + unsigned short base = Exp32Index[-l1-3] + l2 - 9; + if (base < Exp32Index[-l1-2]) { + long lResult = (oddExponent) ? + -Exp32Value[base] : Exp32Value[base]; + /* + * 32-bit number raised to intermediate power, + * done by table lookup + */ + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + if (Tcl_IsShared(valuePtr)) { + TclNewLongObj(objResultPtr, lResult); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + Tcl_SetLongObj(valuePtr, lResult); + TRACE(("%s\n", O2S(valuePtr))); + NEXT_INST_F(1, 1, 0); + } + } +#endif + } + if (type1 == TCL_NUMBER_LONG) { + w1 = l1; +#ifndef NO_WIDE_TYPE + } else if (type1 == TCL_NUMBER_WIDE) { + w1 = *((const Tcl_WideInt*) ptr1); +#endif + } else { + w1 = 0; + } +#if (LONG_MAX > 0x7fffffff) || !defined(TCL_WIDE_INT_IS_LONG) + if (w1 != 0 && type2 == TCL_NUMBER_LONG + && l2 <= 16 + && w1 <= MaxBaseWide[l2-2] && w1 >= -MaxBaseWide[l2-2]) { + /* + * Small powers of integers whose result is wide + */ + Tcl_WideInt wResult = w1 * w1; /* b**2 */ + switch (l2) { + case 2: + break; + case 3: + wResult *= l1; /* b**3 */ + break; + case 4: + wResult *= wResult; /* b**4 */ + break; + case 5: + wResult *= wResult; /* b**4 */ + wResult *= w1; /* b**5 */ + break; + case 6: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + break; + case 7: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + wResult *= w1; /* b**7 */ + break; + case 8: + wResult *= wResult; /* b**4 */ + wResult *= wResult; /* b**8 */ + break; + case 9: + wResult *= wResult; /* b**4 */ + wResult *= wResult; /* b**8 */ + wResult *= w1; /* b**9 */ + break; + case 10: + wResult *= wResult; /* b**4 */ + wResult *= w1; /* b**5 */ + wResult *= wResult; /* b**10 */ + break; + case 11: + wResult *= wResult; /* b**4 */ + wResult *= w1; /* b**5 */ + wResult *= wResult; /* b**10 */ + wResult *= w1; /* b**11 */ + break; + case 12: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + wResult *= wResult; /* b**12 */ + break; + case 13: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + wResult *= wResult; /* b**12 */ + wResult *= w1; /* b**13 */ + break; + case 14: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + wResult *= w1; /* b**7 */ + wResult *= wResult; /* b**14 */ + break; + case 15: + wResult *= w1; /* b**3 */ + wResult *= wResult; /* b**6 */ + wResult *= w1; /* b**7 */ + wResult *= wResult; /* b**14 */ + wResult *= w1; /* b**15 */ + break; + case 16: + wResult *= wResult; /* b**4 */ + wResult *= wResult; /* b**8 */ + wResult *= wResult; /* b**16 */ + break; + + } + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + objResultPtr = Tcl_NewWideIntObj(wResult); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + + /* + * Handle cases of powers > 16 that still fit in a 64-bit + * word by doing table lookup + */ + if (w1 >= 3 + && w1 < (sizeof(Exp64Index) + / sizeof(unsigned short)) - 1) { + unsigned short base = Exp64Index[w1-3] + l2 - 17; + if (base < Exp64Index[w1-2]) { + /* + * 64-bit number raised to intermediate power, + * done by table lookup + */ + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + if (Tcl_IsShared(valuePtr)) { + objResultPtr = Tcl_NewWideIntObj(Exp64Value[base]); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + Tcl_SetWideIntObj(valuePtr, Exp64Value[base]); + TRACE(("%s\n", O2S(valuePtr))); + NEXT_INST_F(1, 1, 0); + } + } + if (-w1 >= 3 + && -w1 < (sizeof(Exp64Index) + / sizeof(unsigned short)) - 1) { + unsigned short base = Exp64Index[-w1-3] + l2 - 17; + if (base < Exp64Index[-w1-2]) { + Tcl_WideInt wResult = (oddExponent) ? + -Exp64Value[base] : Exp64Value[base]; + /* + * 64-bit number raised to intermediate power, + * done by table lookup + */ + TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr))); + if (Tcl_IsShared(valuePtr)) { + objResultPtr = Tcl_NewWideIntObj(wResult); + TRACE(("%s\n", O2S(objResultPtr))); + NEXT_INST_F(1, 2, 1); + } + Tcl_SetWideIntObj(valuePtr, wResult); + TRACE(("%s\n", O2S(valuePtr))); + NEXT_INST_F(1, 1, 0); + } + } +#endif + goto overflow; } diff --git a/tests/expr.test b/tests/expr.test index f73c613..ed8f586 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 1.68 2007/08/08 20:25:05 dgp Exp $ +# RCS: @(#) $Id: expr.test,v 1.69 2007/08/25 03:23:18 kennykb Exp $ if {[lsearch [namespace children] ::tcltest] == -1} { package require tcltest 2.1 @@ -983,7 +983,127 @@ test expr-23.47 {INST_EXPON: Bug 1561260} { test expr-23.48 {INST_EXPON: TIP 274: right assoc} { expr 2**3**4 } 2417851639229258349412352 - +test expr-23.49 {INST_EXPON: optimize powers of 2} { + set trouble {test powers of 2} + for {set tval 0} {$tval <= 66} {incr tval} { + set is [expr {2 ** $tval}] + set sb [expr {1 << $tval}] + if {$is != $sb} { + append trouble \n "2**" $tval " is " $is " should be " $sb + } + if {$tval >= 1} { + set is [expr {-2 ** $tval}] + set sb [expr {1 << $tval}] + if {$tval & 1} { + set sb [expr {-$sb}] + } + if {$is != $sb} { + append trouble \n "-2**" $tval " is " $is " should be " $sb + } + } + } + set trouble +} {test powers of 2} +test expr-23.50 {INST_EXPON: small powers of 32-bit integers} { + set trouble {test small powers of 32-bit ints} + for {set base 3} {$base <= 45} {incr base} { + set sb $base + set sbm [expr {-$base}] + for {set expt 2} {$expt <= 8} {incr expt} { + set sb [expr {$sb * $base}] + set is [expr {$base ** $expt}] + if {$sb != $is} { + append trouble \n $base ** $expt " is " $is " should be " $sb + } + set sbm [expr {-$sbm * $base}] + set ism [expr {(-$base) ** $expt}] + if {$sbm != $ism} { + append trouble \n - $base ** $expt " is " $ism \ + " should be " $sbm + } + } + } + set trouble +} {test small powers of 32-bit ints} +test expr-23.51 {INST_EXPON: intermediate powers of 32-bit integers} { + set trouble {test intermediate powers of 32-bit ints} + for {set base 3} {$base <= 11} {incr base} { + set sb [expr {$base ** 8}] + set sbm $sb + for {set expt 9} {$expt <= 21} {incr expt} { + set sb [expr {$sb * $base}] + set sbm [expr {$sbm * -$base}] + set is [expr {$base ** $expt}] + set ism [expr {-$base ** $expt}] + if {$sb != $is} { + append trouble \n $base ** $expt " is " $is " should be " $sb + } + if {$sbm != $ism} { + append trouble \n - $base ** $expt " is " $ism \ + " should be " $sbm + } + } + } + set trouble +} {test intermediate powers of 32-bit ints} +test expr-23.52 {INST_EXPON: small integer powers with 64-bit results} { + set trouble {test small int powers with 64-bit results} + for {set exp 2} {$exp <= 16} {incr exp} { + set base [expr {entier(pow(double(0x7fffffffffffffff),(1.0/$exp)))}] + set sb 1 + set sbm 1 + for {set i 0} {$i < $exp} {incr i} { + set sb [expr {$sb * $base}] + set sbm [expr {$sbm * -$base}] + } + set is [expr {$base ** $exp}] + set ism [expr {-$base ** $exp}] + if {$sb != $is} { + append trouble \n $base ** $exp " is " $is " should be " $sb + } + if {$sbm != $ism} { + append trouble \n - $base ** $exp " is " $ism " should be " $sbm + } + incr base + set sb 1 + set sbm 1 + for {set i 0} {$i < $exp} {incr i} { + set sb [expr {$sb * $base}] + set sbm [expr {$sbm * -$base}] + } + set is [expr {$base ** $exp}] + set ism [expr {-$base ** $exp}] + if {$sb != $is} { + append trouble \n $base ** $exp " is " $is " should be " $sb + } + if {$sbm != $ism} { + append trouble \n - $base ** $exp " is " $ism " should be " $sbm + } + } + set trouble +} {test small int powers with 64-bit results} +test expr-23.53 {INST_EXPON: intermediate powers of 64-bit integers} { + set trouble {test intermediate powers of 64-bit ints} + for {set base 3} {$base <= 13} {incr base} { + set sb [expr {$base ** 15}] + set sbm [expr {-$sb}] + for {set expt 16} {$expt <= 39} {incr expt} { + set sb [expr {$sb * $base}] + set sbm [expr {$sbm * -$base}] + set is [expr {$base ** $expt}] + set ism [expr {-$base ** $expt}] + if {$sb != $is} { + append trouble \n $base ** $expt " is " $is " should be " $sb + } + if {$sbm != $ism} { + append trouble \n - $base ** $expt " is " $ism \ + " should be " $sbm + } + } + } + set trouble +} {test intermediate powers of 64-bit ints} + # 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 |