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authorBjörn Gustavsson <[email protected]>2017-10-21 07:22:47 +0200
committerBjörn Gustavsson <[email protected]>2017-10-21 07:51:45 +0200
commit19a1af93458ec7a4a252671603d74971f4dec969 (patch)
tree8ada956d105e99a06fd1ef5f0d7ee4dd1f894304
parent6753bbcc3fdb0dd15c8025902d22dc4ec8c33575 (diff)
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Optimize instructions for comparing a register with a literal
We can avoid calling eq() from the is_eq_exact_literal/3 and is_ne_exact_literal/3 instructions if the source operand is an immediate (since a literal is either a boxed or a list, never an immediate).
-rw-r--r--erts/emulator/beam/instrs.tab6
1 files changed, 4 insertions, 2 deletions
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 20d356a81d..c17d1a8f69 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -788,7 +788,8 @@ is_eq_exact(Fail, X, Y) {
}
i_is_eq_exact_literal(Fail, Src, Literal) {
- if (!eq($Src, $Literal)) {
+ Eterm src = $Src;
+ if (is_immed(src) || !eq(src, $Literal)) {
$FAIL($Fail);
}
}
@@ -800,7 +801,8 @@ is_ne_exact(Fail, X, Y) {
}
i_is_ne_exact_literal(Fail, Src, Literal) {
- if (eq($Src, $Literal)) {
+ Eterm src = $Src;
+ if (!is_immed(src) && eq(src, $Literal)) {
$FAIL($Fail);
}
}