Merge branch 'PGPRO_pg_trgm' into PGPRO9_5

vbwagner · vbwagner · commit a58ab6ab8b90 · 2016-02-10T09:02:40.000+03:00
Fix strange bug with early gcc on 32-bit arch
diff --git a/contrib/pg_trgm/trgm_gist.c b/contrib/pg_trgm/trgm_gist.c
@@ -296,7 +296,12 @@ gtrgm_consistent(PG_FUNCTION_ARGS)
 
 			if (GIST_LEAF(entry))
 			{					/* all leafs contains orig trgm */
-				float4		tmpsml = cnt_sml(qtrg, key, *recheck);
+				/*
+				 * Prevent gcc optimizing the tmpsml variable using volatile
+				 * keyword. Otherwise comparison of nlimit and tmpsml may give
+				 * wrong results.
+				 */
+				float4 volatile tmpsml = cnt_sml(qtrg, key, *recheck);
 
 				/* strange bug at freebsd 5.2.1 and gcc 3.3.3 */
 				res = (*(int *) &tmpsml == *(int *) &nlimit || tmpsml > nlimit);
@@ -471,7 +476,13 @@ gtrgm_distance(PG_FUNCTION_ARGS)
 			*recheck = strategy == SubwordDistanceStrategyNumber;
 			if (GIST_LEAF(entry))
 			{					/* all leafs contains orig trgm */
-				res = 1.0 - cnt_sml(qtrg, key, *recheck);
+				/*
+				 * Prevent gcc optimizing the sml variable using volatile
+				 * keyword. Otherwise res can differ from the
+				 * subword_similarity_dist_op() function.
+				 */
+				float4 volatile sml = cnt_sml(qtrg, key, *recheck);
+				res = 1.0 - sml;
 			}
 			else if (ISALLTRUE(key))
 			{					/* all leafs contains orig trgm */
diff --git a/contrib/pg_trgm/trgm_op.c b/contrib/pg_trgm/trgm_op.c
@@ -1157,4 +1157,4 @@ subword_similarity_dist_commutator_op(PG_FUNCTION_ARGS)
 	PG_FREE_IF_COPY(in1, 0);
 	PG_FREE_IF_COPY(in2, 1);
 	PG_RETURN_FLOAT4(1.0 - res);
-}
+}
