diff --git a/src/libCom/calc/calcPerform.c b/src/libCom/calc/calcPerform.c
index 76c0e1623..2221f169f 100644
--- a/src/libCom/calc/calcPerform.c
+++ b/src/libCom/calc/calcPerform.c
@@ -45,6 +45,7 @@ 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;
 
@@ -262,7 +263,7 @@ epicsShareFunc long
 
 	case NINT:
 	    top = *ptop;
-	    *ptop = (double)(epicsInt32)(top >= 0 ? top + 0.5 : top - 0.5);
+	    *ptop = (epicsInt32) (top >= 0 ? top + 0.5 : top - 0.5);
 	    break;
 
 	case RANDOM:
@@ -283,34 +284,45 @@ 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.
+         */
+
 	case BIT_OR:
-        itop = (epicsUInt32) *ptop--;
-        *ptop = (epicsInt32) ((epicsUInt32)*ptop | itop);
+	    utop = *ptop--;
+	    *ptop = (epicsInt32) ((epicsUInt32) *ptop | utop);
 	    break;
 
 	case BIT_AND:
-        itop = (epicsUInt32) *ptop--;
-        *ptop = (epicsInt32) ((epicsUInt32) *ptop & itop);
+	    utop = *ptop--;
+	    *ptop = (epicsInt32) ((epicsUInt32) *ptop & utop);
 	    break;
 
 	case BIT_EXCL_OR:
-        itop = (epicsUInt32) *ptop--;
-        *ptop = (epicsInt32) ((epicsUInt32) *ptop ^ itop);
+	    utop = *ptop--;
+	    *ptop = (epicsInt32) ((epicsUInt32) *ptop ^ utop);
 	    break;
 
 	case BIT_NOT:
-        itop = (epicsUInt32) *ptop;
-	    *ptop = ~itop;
+	    utop = *ptop;
+	    *ptop = (epicsInt32) ~utop;
 	    break;
 
+        /* The shift operators use signed integers, so a right-shift will
+         * extend the sign bit into the left-hand end of the value. The
+         * double-casting through unsigned here is important, see above.
+         */
+
 	case RIGHT_SHIFT:
-	    itop = (epicsInt32) *ptop--;
-        *ptop = (epicsInt32) (epicsUInt32) *ptop >> itop;
+	    utop = *ptop--;
+	    *ptop = ((epicsInt32) (epicsUInt32) *ptop) >> (utop & 31);
 	    break;
 
 	case LEFT_SHIFT:
-	    itop = (epicsInt32) *ptop--;
-        *ptop = (epicsInt32) ((epicsUInt32) *ptop << itop);
+	    utop = *ptop--;
+	    *ptop = ((epicsInt32) (epicsUInt32) *ptop) << (utop & 31);
 	    break;
 
 	case NOT_EQ:
diff --git a/src/libCom/calc/postfix.c b/src/libCom/calc/postfix.c
index 4ad57f910..d64d00d85 100644
--- a/src/libCom/calc/postfix.c
+++ b/src/libCom/calc/postfix.c
@@ -602,13 +602,13 @@ epicsShareFunc void
     while ((op = *pinst) != END_EXPRESSION) {
 	switch (op) {
 	case LITERAL_DOUBLE:
-        memcpy(&lit_d, ++pinst, sizeof(double));
+	    memcpy(&lit_d, ++pinst, sizeof(double));
 	    printf("\tDouble %g\n", lit_d);
 	    pinst += sizeof(double);
 	    break;
 	case LITERAL_INT:
-        memcpy(&lit_i, ++pinst, sizeof(epicsInt32));
-        printf("\tInteger %d (0x%x)\n", lit_i, lit_i);
+	    memcpy(&lit_i, ++pinst, sizeof(epicsInt32));
+	    printf("\tInteger %d (0x%x)\n", lit_i, lit_i);
 	    pinst += sizeof(int);
 	    break;
 	case MIN:
diff --git a/src/libCom/test/epicsCalcTest.cpp b/src/libCom/test/epicsCalcTest.cpp
index 5b17694f9..b5199ac15 100644
--- a/src/libCom/test/epicsCalcTest.cpp
+++ b/src/libCom/test/epicsCalcTest.cpp
@@ -64,7 +64,6 @@ void testCalc(const char *expr, double expected) {
         testDiag("Expected result is %g, actually got %g", expected, result);
         calcExprDump(rpn);
     }
-    return;
 }
 
 void testUInt32Calc(const char *expr, epicsUInt32 expected) {
@@ -93,7 +92,6 @@ void testUInt32Calc(const char *expr, epicsUInt32 expected) {
                  expected, expected, uresult, uresult);
         calcExprDump(rpn);
     }
-    return;
 }
 
 void testArgs(const char *expr, unsigned long einp, unsigned long eout) {
@@ -931,16 +929,16 @@ MAIN(epicsCalcTest)
     testUInt32Calc("a:=0xaaaaaaaa; ~~a", 0xaaaaaaaau);
     testUInt32Calc("a:=0xaaaaaaaa; a >> 8", 0xffaaaaaau);
     testUInt32Calc("a:=0xaaaaaaaa; a << 8", 0xaaaaaa00u);
-    //   using double operands (what the calc record does)
-    //     0xaaaaaaaa = 2863311530.0
-    //     0xffff0000 = 4294901760.0
-    testUInt32Calc("a:=2863311530.0; b:=4294901760.0; a AND b", 0xaaaa0000u);
-    testUInt32Calc("a:=2863311530.0; b:=4294901760.0; a OR b", 0xffffaaaau);
-    testUInt32Calc("a:=2863311530.0; b:=4294901760.0; a XOR b", 0x5555aaaau);
-    testUInt32Calc("a:=2863311530.0; ~a", 0x55555555u);
-    testUInt32Calc("a:=2863311530.0; ~~a", 0xaaaaaaaau);
-    testUInt32Calc("a:=2863311530.0; a >> 8", 0xffaaaaaau);
-    testUInt32Calc("a:=2863311530.0; a << 8", 0xaaaaaa00u);
+    //   using double operands (add 0.1 to force as double)
+    //     0xaaaaaaaa = -1431655766
+    //     0xffff0000 = -65536
+    testUInt32Calc("a:=-1431655766.1; b:=-65536.1; a AND b", 0xaaaa0000u);
+    testUInt32Calc("a:=-1431655766.1; b:=-65536.1; a OR b", 0xffffaaaau);
+    testUInt32Calc("a:=-1431655766.1; b:=-65536.1; a XOR b", 0x5555aaaau);
+    testUInt32Calc("a:=-1431655766.1; ~a", 0x55555555u);
+    testUInt32Calc("a:=-1431655766.1; ~~a", 0xaaaaaaaau);
+    testUInt32Calc("a:=-1431655766.1; a >> 8", 0xffaaaaaau);
+    testUInt32Calc("a:=-1431655766.1; a << 8", 0xaaaaaa00u);
 
     return testDone();
 }