Revision: 16735
Author: svenpa...@chromium.org
Date: Mon Sep 16 13:51:14 2013 UTC
Log: In the case of shift amounts with two constants and if their sum
is equal 32, then shift can also be replaced with bit rotate.
R=svenpa...@chromium.org
Review URL: https://codereview.chromium.org/24095002
Patch from Bangfu Tao <bangfu....@samsung.com>.
http://code.google.com/p/v8/source/detail?r=16735
Modified:
/branches/bleeding_edge/src/hydrogen.cc
/branches/bleeding_edge/test/mjsunit/compiler/rotate.js
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Mon Sep 16 11:30:10 2013 UTC
+++ /branches/bleeding_edge/src/hydrogen.cc Mon Sep 16 13:51:14 2013 UTC
@@ -7633,9 +7633,16 @@
}
-// Checks if the given shift amounts have form: (sa) and (32 - sa).
+// Checks if the given shift amounts have following forms:
+// (N1) and (N2) with N1 + N2 = 32; (sa) and (32 - sa).
static bool ShiftAmountsAllowReplaceByRotate(HValue* sa,
HValue* const32_minus_sa) {
+ if (sa->IsConstant() && const32_minus_sa->IsConstant()) {
+ const HConstant* c1 = HConstant::cast(sa);
+ const HConstant* c2 = HConstant::cast(const32_minus_sa);
+ return c1->HasInteger32Value() && c2->HasInteger32Value() &&
+ (c1->Integer32Value() + c2->Integer32Value() == 32);
+ }
if (!const32_minus_sa->IsSub()) return false;
HSub* sub = HSub::cast(const32_minus_sa);
if (sa != sub->right()) return false;
=======================================
--- /branches/bleeding_edge/test/mjsunit/compiler/rotate.js Mon Nov 5
13:28:10 2012 UTC
+++ /branches/bleeding_edge/test/mjsunit/compiler/rotate.js Mon Sep 16
13:51:14 2013 UTC
@@ -222,3 +222,89 @@
assertEquals(1 << ((i % 32)), ROR4(1, i));
}
+//---------------------------------------------------------
+// add test cases for constant operand
+//---------------------------------------------------------
+// constant operand: 20
+function ROR1_sa20(x) {
+ return (x >>> 20) | (x << 12);
+}
+
+function ROR2_sa20(x) {
+ return (x >>> 12) | (x << 20);
+}
+
+function ROR3_sa20(x, sa) {
+ return (x << 12) | (x >>> 20);
+}
+
+function ROR4_sa20(x) {
+ return (x << 20) | (x >>> 12);
+}
+
+// constant operand: 40
+function ROR1_sa40(x) {
+ return (x >>> 40) | (x << -8);
+}
+
+function ROR2_sa40(x) {
+ return (x >>> -8) | (x << 40);
+}
+
+function ROR3_sa40(x, sa) {
+ return (x << -8) | (x >>> 40);
+}
+
+function ROR4_sa40(x) {
+ return (x << 40) | (x >>> -8);
+}
+
+// ROR1_sa20
+assertEquals(ROR1(0x0000FFFF, 20), ROR1_sa20(0x0000FFFF));
+assertEquals(ROR1(0x0000FFFF, 20), ROR1_sa20(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR1_sa20);
+assertEquals(ROR1(0x0000FFFF, 20), ROR1_sa20(0x0000FFFF));
+
+// ROR1_sa40
+assertEquals(ROR1(0x0000FFFF, 40), ROR1_sa40(0x0000FFFF));
+assertEquals(ROR1(0x0000FFFF, 40), ROR1_sa40(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR1_sa40);
+assertEquals(ROR1(0x0000FFFF, 40), ROR1_sa40(0x0000FFFF));
+
+// ROR2_sa20
+assertEquals(ROR2(0xFFFFFFFF, 20), ROR2_sa20(0xFFFFFFFF));
+assertEquals(ROR2(0xFFFFFFFF, 20), ROR2_sa20(0xFFFFFFFF));
+%OptimizeFunctionOnNextCall(ROR2_sa20);
+assertEquals(ROR2(0xFFFFFFFF, 20), ROR2_sa20(0xFFFFFFFF));
+
+// ROR2_sa40
+assertEquals(ROR2(0x0000FFFF, 40), ROR2_sa40(0x0000FFFF));
+assertEquals(ROR2(0x0000FFFF, 40), ROR2_sa40(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR2_sa40);
+assertEquals(ROR2(0x0000FFFF, 40), ROR2_sa40(0x0000FFFF));
+
+// ROR3_sa20
+assertEquals(ROR3(0x0000FFFF, 20), ROR3_sa20(0x0000FFFF));
+assertEquals(ROR3(0x0000FFFF, 20), ROR3_sa20(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR3_sa20);
+assertEquals(ROR3(0x0000FFFF, 20), ROR3_sa20(0x0000FFFF));
+
+// ROR3_sa40
+assertEquals(ROR3(0x0000FFFF, 40), ROR3_sa40(0x0000FFFF));
+assertEquals(ROR3(0x0000FFFF, 40), ROR3_sa40(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR3_sa40);
+assertEquals(ROR3(0x0000FFFF, 40), ROR3_sa40(0x0000FFFF));
+
+// ROR4_sa20
+assertEquals(ROR4(0x0000FFFF, 20), ROR4_sa20(0x0000FFFF));
+assertEquals(ROR4(0x0000FFFF, 20), ROR4_sa20(0x0000FFFF));
+%OptimizeFunctionOnNextCall(ROR4_sa20);
+assertEquals(ROR4(0x0000FFFF, 20), ROR4_sa20(0x0000FFFF));
+
+// ROR4_sa40
+assertEquals(ROR4(0xFFFFFFFF, 40), ROR4_sa40(0xFFFFFFFF));
+assertEquals(ROR4(0xFFFFFFFF, 40), ROR4_sa40(0xFFFFFFFF));
+%OptimizeFunctionOnNextCall(ROR4_sa40);
+assertEquals(ROR4(0xFFFFFFFF, 40), ROR4_sa40(0xFFFFFFFF));
+
+
--
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