cpp/openttd-patchpack/source Changeset - r21376:6c94a5a545a2

Changeset - r21376:6c94a5a545a2

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rubidium - 10 years ago 2014-04-20 15:47:50
rubidium@openttd.org

(svn r26475) -Fix: potentially undefined shifts in NewGRF code

2 files changed with 5 insertions and 5 deletions:

src/newgrf.cpp

src/newgrf_spritegroup.cpp

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src/newgrf.cpp

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@@ @@ -6736,7 +6736,7 @@ static void ParamSet(ByteReader *buf) @@
 			if ((int32)src2 < 0) {
 				res = src1 >> -(int32)src2;
 			} else {
 				res = src1 << src2;
+				res = src1 << (src2 & 0x1F); // Same behaviour as in EvalAdjustT, mask 'value' to 5 bits, which should behave the same on all architectures.
+			}
 			break;
@@ @@ -6744,7 +6744,7 @@ static void ParamSet(ByteReader *buf) @@
 			if ((int32)src2 < 0) {
 				res = (int32)src1 >> -(int32)src2;
 			} else {
 				res = (int32)src1 << src2;
+				res = (int32)src1 << (src2 & 0x1F); // Same behaviour as in EvalAdjustT, mask 'value' to 5 bits, which should behave the same on all architectures.
+			}
 			break;

src/newgrf_spritegroup.cpp

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@@ @@ -228,9 +228,9 @@ static U EvalAdjustT(const Deterministic @@
 		case DSGA_OP_ROR:  return RotateRight(last_value, value);
 		case DSGA_OP_SCMP: return ((S)last_value == (S)value) ? 1 : ((S)last_value < (S)value ? 0 : 2);
 		case DSGA_OP_UCMP: return ((U)last_value == (U)value) ? 1 : ((U)last_value < (U)value ? 0 : 2);
 		case DSGA_OP_SHL:  return (U)last_value << ((U)value & 0x1F); // mask 'value' to 5 bits, which should behave the same on all architectures.
 		case DSGA_OP_SHR:  return (U)last_value >> ((U)value & 0x1F);
 		case DSGA_OP_SAR:  return (S)last_value >> ((U)value & 0x1F);
 		case DSGA_OP_SHL:  return (uint32)(U)last_value << ((U)value & 0x1F); // Same behaviour as in ParamSet, mask 'value' to 5 bits, which should behave the same on all architectures.
 		case DSGA_OP_SHR:  return (uint32)(U)last_value >> ((U)value & 0x1F);
 		case DSGA_OP_SAR:  return (int32)(S)last_value >> ((U)value & 0x1F);
 		default:           return value;
+	}
+}

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