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authorBjörn-Egil Dahlberg <[email protected]>2015-05-07 16:50:52 +0200
committerBjörn-Egil Dahlberg <[email protected]>2015-05-07 16:50:52 +0200
commitb17d18510c013b5077c57e778b6e1bf0f8784395 (patch)
treeeb06ea1198cbfe62dc70943b0baad255912e5225
parent7b9a2c6b90cc6f41b0f42198e474a9322a4f2a94 (diff)
parent889dbf81def0986e4569841d64a7f3882808ee07 (diff)
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Merge branch 'egil/fix-pos-zero-opt'
* egil/fix-pos-zero-opt: erts: Don't let the compiler optimize pos. zero fix
-rw-r--r--erts/emulator/beam/erl_arith.c5
-rw-r--r--erts/emulator/beam/global.h3
-rw-r--r--erts/emulator/beam/utils.c12
3 files changed, 16 insertions, 4 deletions
diff --git a/erts/emulator/beam/erl_arith.c b/erts/emulator/beam/erl_arith.c
index 5150a8a507..47d516534f 100644
--- a/erts/emulator/beam/erl_arith.c
+++ b/erts/emulator/beam/erl_arith.c
@@ -2048,3 +2048,8 @@ Eterm erts_gc_bnot(Process* p, Eterm* reg, Uint live)
}
return result;
}
+
+/* Needed to remove compiler optimization */
+double erts_get_positive_zero_float() {
+ return 0.0f;
+}
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 40b043d1cc..54fba9274f 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -867,6 +867,9 @@ void print_process_info(int, void *, Process*);
void info(int, void *);
void loaded(int, void *);
+/* erl_arith.c */
+double erts_get_positive_zero_float(void);
+
/* config.c */
__decl_noreturn void __noreturn erl_exit(int n, char*, ...);
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 8f6335d5dd..51de3528be 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -958,7 +958,8 @@ tail_recur:
FloatDef ff;
GET_DOUBLE(term, ff);
if (ff.fd == 0.0f) {
- ff.fd = 0.0f; /* ensure pos. 0.0 */
+ /* ensure positive 0.0 */
+ ff.fd = erts_get_positive_zero_float();
}
hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]);
break;
@@ -1477,7 +1478,8 @@ make_hash2(Eterm term)
FloatDef ff;
GET_DOUBLE(term, ff);
if (ff.fd == 0.0f) {
- ff.fd = 0.0f; /* ensure pos. 0.0 */
+ /* ensure positive 0.0 */
+ ff.fd = erts_get_positive_zero_float();
}
#if defined(WORDS_BIGENDIAN) || defined(DOUBLE_MIDDLE_ENDIAN)
UINT32_HASH_2(ff.fw[0], ff.fw[1], HCONST_12);
@@ -1899,7 +1901,8 @@ make_internal_hash(Eterm term)
FloatDef ff;
GET_DOUBLE(term, ff);
if (ff.fd == 0.0f) {
- ff.fd = 0.0f; /* ensure pos. 0.0 */
+ /* ensure positive 0.0 */
+ ff.fd = erts_get_positive_zero_float();
}
UINT32_HASH_2(ff.fw[0], ff.fw[1], HCONST_12);
goto pop_next;
@@ -2087,7 +2090,8 @@ tail_recur:
FloatDef ff;
GET_DOUBLE(term, ff);
if (ff.fd == 0.0f) {
- ff.fd = 0.0f; /* ensure pos. 0.0 */
+ /* ensure positive 0.0 */
+ ff.fd = erts_get_positive_zero_float();
}
hash = hash*FUNNY_NUMBER6 + (ff.fw[0] ^ ff.fw[1]);
}