Freddie Akeroyd has proposed merging ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15.
Commit message:
Fix bit operations failures on VS2019 32bit
Working with Dirk Zimoch @dirk.zimoch, fixed various issues
with bit operations on VS2019 32bit. These seem to relate to
handling bit 31 of a 32 bit number.
As EPICS << is an arithmetic bit shift, following Java we
have added <<< and >>> operators for logical shifts
Though it is on a different architecture, this looks like
a similar issue to LP: #1838792
Requested reviews:
EPICS Core Developers (epics-core)
Related bugs:
Bug #1838792 in EPICS Base: "epicsCalc bit-wise operators on aarch64"
https://bugs.launchpad.net/epics-base/+bug/1838792
For more details, see:
https://code.launchpad.net/~freddie-akeroyd/epics-base/+git/epics-base/+merge/379191
--
Your team EPICS Core Developers is requested to review the proposed merge of ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15.
diff --git a/src/libCom/calc/calcPerform.c b/src/libCom/calc/calcPerform.c
index c0f4aeb..1d675cf 100644
--- a/src/libCom/calc/calcPerform.c
+++ b/src/libCom/calc/calcPerform.c
@@ -33,7 +33,7 @@ static int cond_search(const char **ppinst, int match);
#endif
/* Turn off global optimization for 64-bit MSVC builds */
-#if defined(_WIN32) && defined(_M_X64) && !defined(_MINGW)
+#if 0 && defined(_WIN32) && defined(_M_X64) && !defined(_MINGW)
# pragma optimize("g", off)
#endif
@@ -48,7 +48,6 @@ epicsShareFunc long
double *ptop; /* stack pointer */
double top; /* value from top of stack */
epicsInt32 itop; /* integer from top of stack */
- epicsUInt32 utop; /* unsigned integer from top of stack */
int op;
int nargs;
@@ -287,30 +286,37 @@ epicsShareFunc long
*ptop = ! *ptop;
break;
- /* For bitwise operations on values with bit 31 set, double values
- * must first be cast to unsigned to correctly set that bit; the
- * double value must be negative in that case. The result must be
- * cast to a signed integer before converting to the double result.
+ /* Be VERY careful converting double to int in case bit 31 is set!
+ * Out-of-range errors give very different results on different sytems.
+ * Convert negative doubles to signed and positive doubles to unsigned
+ * first to avoid overflows if bit 32 is set.
+ * The result is always signed, values with bit 31 set are negative
+ * to avoid problems when writing the value to signed integer fields
+ * like longout.VAL or ao.RVAL. However unsigned fields may give
+ * problems on some architectures. (Fewer than giving problems with
+ * signed integer. Maybe the conversion functions should handle
+ * overflows better.)
*/
+ #define d2i(x) ((x)<0?(epicsInt32)(x):(epicsInt32)(epicsUInt32)(x))
+ #define d2ui(x) ((x)<0?(epicsUInt32)(epicsInt32)(x):(epicsUInt32)(x))
case BIT_OR:
- utop = *ptop--;
- *ptop = (epicsInt32) ((epicsUInt32) *ptop | utop);
+ top = *ptop--;
+ *ptop = (double)(d2i(*ptop) | d2i(top));
break;
case BIT_AND:
- utop = *ptop--;
- *ptop = (epicsInt32) ((epicsUInt32) *ptop & utop);
+ top = *ptop--;
+ *ptop = (double)(d2i(*ptop) & d2i(top));
break;
case BIT_EXCL_OR:
- utop = *ptop--;
- *ptop = (epicsInt32) ((epicsUInt32) *ptop ^ utop);
+ top = *ptop--;
+ *ptop = (double)(d2i(*ptop) ^ d2i(top));
break;
case BIT_NOT:
- utop = *ptop;
- *ptop = (epicsInt32) ~utop;
+ *ptop = (double)~d2i(*ptop);
break;
/* The shift operators use signed integers, so a right-shift will
@@ -318,14 +324,24 @@ epicsShareFunc long
* double-casting through unsigned here is important, see above.
*/
- case RIGHT_SHIFT:
- utop = *ptop--;
- *ptop = ((epicsInt32) (epicsUInt32) *ptop) >> (utop & 31);
+ case RIGHT_SHIFT_ARITH:
+ top = *ptop--;
+ *ptop = (double)(d2i(*ptop) >> (d2i(top) & 31));
break;
- case LEFT_SHIFT:
- utop = *ptop--;
- *ptop = ((epicsInt32) (epicsUInt32) *ptop) << (utop & 31);
+ case LEFT_SHIFT_ARITH:
+ top = *ptop--;
+ *ptop = (double)(d2i(*ptop) << (d2i(top) & 31));
+ break;
+
+ case RIGHT_SHIFT_LOGIC:
+ top = *ptop--;
+ *ptop = (double)(d2ui(*ptop) >> (d2ui(top) & 31u));
+ break;
+
+ case LEFT_SHIFT_LOGIC:
+ top = *ptop--;
+ *ptop = (double)(d2ui(*ptop) << (d2ui(top) & 31u));
break;
case NOT_EQ:
@@ -382,11 +398,12 @@ epicsShareFunc long
*presult = *ptop;
return 0;
}
-#if defined(_WIN32) && defined(_M_X64) && !defined(_MINGW)
+#if 0 && defined(_WIN32) && defined(_M_X64) && !defined(_MINGW)
# pragma optimize("", on)
#endif
-
+
+
epicsShareFunc long
calcArgUsage(const char *pinst, unsigned long *pinputs, unsigned long *pstores)
{
diff --git a/src/libCom/calc/postfix.c b/src/libCom/calc/postfix.c
index 463ceea..cf54eb8 100644
--- a/src/libCom/calc/postfix.c
+++ b/src/libCom/calc/postfix.c
@@ -148,13 +148,15 @@ static const ELEMENT operators[] = {
{":=", 0, 0, -1, STORE_OPERATOR, STORE_A},
{";", 0, 0, 0, EXPR_TERMINATOR,NOT_GENERATED},
{"<", 3, 3, -1, BINARY_OPERATOR,LESS_THAN},
-{"<<", 2, 2, -1, BINARY_OPERATOR,LEFT_SHIFT},
+{"<<", 2, 2, -1, BINARY_OPERATOR,LEFT_SHIFT_ARITH},
+{"<<<", 2, 2, -1, BINARY_OPERATOR,LEFT_SHIFT_LOGIC},
{"<=", 3, 3, -1, BINARY_OPERATOR,LESS_OR_EQ},
{"=", 3, 3, -1, BINARY_OPERATOR,EQUAL},
{"==", 3, 3, -1, BINARY_OPERATOR,EQUAL},
{">", 3, 3, -1, BINARY_OPERATOR,GR_THAN},
{">=", 3, 3, -1, BINARY_OPERATOR,GR_OR_EQ},
-{">>", 2, 2, -1, BINARY_OPERATOR,RIGHT_SHIFT},
+{">>", 2, 2, -1, BINARY_OPERATOR,RIGHT_SHIFT_ARITH},
+{">>>", 2, 2, -1, BINARY_OPERATOR,RIGHT_SHIFT_LOGIC},
{"?", 0, 0, -1, CONDITIONAL, COND_IF},
{"AND", 2, 2, -1, BINARY_OPERATOR,BIT_AND},
{"OR", 1, 1, -1, BINARY_OPERATOR,BIT_OR},
@@ -579,8 +581,10 @@ epicsShareFunc void
"BIT_AND",
"BIT_EXCL_OR",
"BIT_NOT",
- "RIGHT_SHIFT",
- "LEFT_SHIFT",
+ "RIGHT_SHIFT_ARITH",
+ "RIGHT_SHIFT_LOGIC",
+ "LEFT_SHIFT_ARITH",
+ "LEFT_SHIFT_LOGIC",
/* Relationals */
"NOT_EQ",
"LESS_THAN",
diff --git a/src/libCom/calc/postfixPvt.h b/src/libCom/calc/postfixPvt.h
index 53efb32..5b2ba0a 100644
--- a/src/libCom/calc/postfixPvt.h
+++ b/src/libCom/calc/postfixPvt.h
@@ -84,8 +84,10 @@ typedef enum {
BIT_AND,
BIT_EXCL_OR,
BIT_NOT,
- RIGHT_SHIFT,
- LEFT_SHIFT,
+ RIGHT_SHIFT_ARITH,
+ RIGHT_SHIFT_LOGIC,
+ LEFT_SHIFT_ARITH,
+ LEFT_SHIFT_LOGIC,
/* Relationals */
NOT_EQ,
LESS_THAN,
diff --git a/src/libCom/test/epicsCalcTest.cpp b/src/libCom/test/epicsCalcTest.cpp
index 2492c95..a0131cd 100644
--- a/src/libCom/test/epicsCalcTest.cpp
+++ b/src/libCom/test/epicsCalcTest.cpp
@@ -104,7 +104,7 @@ void testUInt32Calc(const char *expr, epicsUInt32 expected) {
testDiag("calcPerform: error evaluating '%s'", expr);
}
- uresult = (epicsUInt32) result;
+ uresult = (result < 0.0 ? (epicsUInt32)(epicsInt32)result : (epicsUInt32)result);
pass = (uresult == expected);
if (!testOk(pass, "%s", expr)) {
testDiag("Expected result is 0x%x (%u), actually got 0x%x (%u)",
@@ -297,7 +297,7 @@ MAIN(epicsCalcTest)
const double a=1.0, b=2.0, c=3.0, d=4.0, e=5.0, f=6.0,
g=7.0, h=8.0, i=9.0, j=10.0, k=11.0, l=12.0;
- testPlan(613);
+ testPlan(643);
/* LITERAL_OPERAND elements */
testExpr(0);
@@ -688,7 +688,9 @@ MAIN(epicsCalcTest)
testExpr(NaN < NaN);
testExpr(1 << 2);
- testExpr(1 << 3 << 2)
+ testCalc("1 <<< 2", 1u << 2u);
+ testExpr(1 << 3 << 2);
+ testCalc("1 <<< 3 <<< 2", 1u << 3u << 2u);
testExpr(0 <= 1);
testExpr(0 <= 0);
@@ -776,7 +778,9 @@ MAIN(epicsCalcTest)
testExpr(NaN >= NaN);
testExpr(8 >> 1);
+ testCalc("8 >>> 1", 8u >> 1u);
testExpr(64 >> 2 >> 1);
+ testCalc("64 >>> 2 >>> 1", 64u >> 2u >> 1u);
testExpr(7 AND 4);
@@ -873,13 +877,19 @@ MAIN(epicsCalcTest)
testExpr(2 | 4 / 2); // 1 5
testCalc("1 | 2 ** 3", 1 | (int) pow(2., 3.));// 1 6
testExpr(3 << 2 & 10); // 2 2
+ testCalc("3 <<< 2 & 10", 3u << 2u & 10u); // 2 2
testCalc("18 & 6 << 2", (18 & 6) << 2); // 2 2
+ testCalc("18 & 6 <<< 2", (18u & 6u) << 2u); // 2 2
testExpr(36 >> 2 & 10); // 2 2
+ testCalc("36 >>> 2 & 10", 36u >> 2u & 10u); // 2 2
testCalc("18 & 20 >> 2", (18 & 20) >> 2); // 2 2
+ testCalc("18 & 20 >>> 2", (18u & 20u) >> 2u); // 2 2
testExpr(3 & 4 == 4); // 2 3
testExpr(3 AND 4 == 4); // 2 3
testCalc("1 << 2 != 4", 1 << (2 != 4)); // 2 3
+ testCalc("1 <<< 2 != 4", 1u << (2u != 4u)); // 2 3
testCalc("16 >> 2 != 4", 16 >> (2 != 4)); // 2 3
+ testCalc("16 >>> 2 != 4", 16u >> (2u != 4u)); // 2 3
testExpr(3 AND -2); // 2 8
testExpr(0 < 1 ? 2 : 3); // 3 0
testExpr(1 <= 0 ? 2 : 3); // 3 0
@@ -951,7 +961,13 @@ MAIN(epicsCalcTest)
testUInt32Calc("~0xaaaaaaaa", 0x55555555u);
testUInt32Calc("~~0xaaaaaaaa", 0xaaaaaaaau);
testUInt32Calc("0xaaaaaaaa >> 8", 0xffaaaaaau);
+ testUInt32Calc("0x55555555 >> 8", 0x00555555u);
+ testUInt32Calc("0xaaaaaaaa >>> 8", 0x00aaaaaau);
+ testUInt32Calc("0x55555555 >>> 8", 0x00555555u);
testUInt32Calc("0xaaaaaaaa << 8", 0xaaaaaa00u);
+ testUInt32Calc("0x55555555 << 8", 0x55555500u);
+ testUInt32Calc("0xaaaaaaaa <<< 8", 0xaaaaaa00u);
+ testUInt32Calc("0x55555555 <<< 8", 0x55555500u);
// using integer literals assigned to variables
testUInt32Calc("a:=0xaaaaaaaa; b:=0xffff0000; a AND b", 0xaaaa0000u);
testUInt32Calc("a:=0xaaaaaaaa; b:=0xffff0000; a OR b", 0xffffaaaau);
@@ -959,7 +975,13 @@ MAIN(epicsCalcTest)
testUInt32Calc("a:=0xaaaaaaaa; ~a", 0x55555555u);
testUInt32Calc("a:=0xaaaaaaaa; ~~a", 0xaaaaaaaau);
testUInt32Calc("a:=0xaaaaaaaa; a >> 8", 0xffaaaaaau);
+ testUInt32Calc("a:=0xaaaaaaaa; a >>> 8", 0x00aaaaaau);
testUInt32Calc("a:=0xaaaaaaaa; a << 8", 0xaaaaaa00u);
+ testUInt32Calc("a:=0xaaaaaaaa; a <<< 8", 0xaaaaaa00u);
+ testUInt32Calc("a:=0x55555555; a >> 8", 0x00555555u);
+ testUInt32Calc("a:=0x55555555; a >>> 8", 0x00555555u);
+ testUInt32Calc("a:=0x55555555; a << 8", 0x55555500u);
+ testUInt32Calc("a:=0x55555555; a <<< 8", 0x55555500u);
// Test proper conversion of double values (+ 0.1 enforces double literal)
// when used as inputs to the bitwise operations.
@@ -979,14 +1001,21 @@ MAIN(epicsCalcTest)
testUInt32Calc("~ -1431655766.1", 0x55555555u);
testUInt32Calc("~ 2863311530.1", 0x55555555u);
testUInt32Calc("-1431655766.1 >> 0", 0xaaaaaaaau);
+ testUInt32Calc("-1431655766.1 >>> 0", 0xaaaaaaaau);
testUInt32Calc("2863311530.1 >> 0", 0xaaaaaaaau);
+ testUInt32Calc("2863311530.1 >>> 0", 0xaaaaaaaau);
testUInt32Calc("-1431655766.1 >> 0.1", 0xaaaaaaaau);
+ testUInt32Calc("-1431655766.1 >>> 0.1", 0xaaaaaaaau);
testUInt32Calc("2863311530.1 >> 0.1", 0xaaaaaaaau);
+ testUInt32Calc("2863311530.1 >>> 0.1", 0xaaaaaaaau);
testUInt32Calc("-1431655766.1 << 0", 0xaaaaaaaau);
+ testUInt32Calc("-1431655766.1 <<< 0", 0xaaaaaaaau);
testUInt32Calc("2863311530.1 << 0", 0xaaaaaaaau);
+ testUInt32Calc("2863311530.1 <<< 0", 0xaaaaaaaau);
testUInt32Calc("-1431655766.1 << 0.1", 0xaaaaaaaau);
+ testUInt32Calc("-1431655766.1 <<< 0.1", 0xaaaaaaaau);
testUInt32Calc("2863311530.1 << 0.1", 0xaaaaaaaau);
+ testUInt32Calc("2863311530.1 <<< 0.1", 0xaaaaaaaau);
return testDone();
}
-
- Replies:
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 mdavidsaver via Core-talk
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 mdavidsaver via Core-talk
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 Martin Konrad via Core-talk
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 Freddie Akeroyd via Core-talk
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 Freddie Akeroyd via Core-talk
- Re: [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 Freddie Akeroyd via Core-talk
- [Merge] ~freddie-akeroyd/epics-base:bit_operations into epics-base:3.15 noreply--- via Core-talk
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