commit 07f712f6d083ec0589e7a0c5e4712809eea19a30
author Chris Larsen <chris.larsen@imgtec.com> Fri Jun 10 16:06:02 2016 -0700
committer Chris Larsen <chris.larsen@imgtec.com> Mon Jul 11 08:22:21 2016 -0700
tree 5e91526e22cde45d4d5f7953a86eafc90ae99ef8
parent dadc075149eb322bf28ba35a75a70157147c1c30

MIPS32: Optimize R6 round(float) intrinsic.

Remove two instructions when calculating java.lang.Math.round(float).

Change-Id: Ic2091c0136d87b43963bac9480e03377fbc2d671

compiler/optimizing/intrinsics_mips.cc

diff --git a/compiler/optimizing/intrinsics_mips.cc b/compiler/optimizing/intrinsics_mips.cc
index d4f44d6..7137fd9 100644
--- a/compiler/optimizing/intrinsics_mips.cc
+++ b/compiler/optimizing/intrinsics_mips.cc
@@ -2457,16 +2457,18 @@
   __ FloorWS(FTMP, in);
   __ Mfc1(out, FTMP);
 
-  __ LoadConst32(TMP, 1);
+  if (!IsR6()) {
+    __ LoadConst32(TMP, -1);
+  }
 
-  // TMP = (out = java.lang.Integer.MAX_VALUE) ? 1 : 0;
+  // TMP = (out = java.lang.Integer.MAX_VALUE) ? -1 : 0;
   __ LoadConst32(AT, std::numeric_limits<int32_t>::max());
   __ Bne(AT, out, &finite);
 
   __ Mtc1(ZERO, FTMP);
   if (IsR6()) {
     __ CmpLtS(FTMP, in, FTMP);
-    __ Mfc1(AT, FTMP);
+    __ Mfc1(TMP, FTMP);
   } else {
     __ ColtS(in, FTMP);
   }
@@ -2475,28 +2477,26 @@
 
   __ Bind(&finite);
 
-  // TMP = (0.5f <= (in - out)) ? 1 : 0;
+  // TMP = (0.5f <= (in - out)) ? -1 : 0;
   __ Cvtsw(FTMP, FTMP);  // Convert output of floor.w.s back to "float".
   __ LoadConst32(AT, bit_cast<int32_t, float>(0.5f));
   __ SubS(FTMP, in, FTMP);
   __ Mtc1(AT, half);
   if (IsR6()) {
     __ CmpLeS(FTMP, half, FTMP);
-    __ Mfc1(AT, FTMP);
+    __ Mfc1(TMP, FTMP);
   } else {
     __ ColeS(half, FTMP);
   }
 
   __ Bind(&add);
 
-  if (IsR6()) {
-    __ Selnez(TMP, TMP, AT);
-  } else {
+  if (!IsR6()) {
     __ Movf(TMP, ZERO);
   }
 
-  // Return out += TMP.
-  __ Addu(out, out, TMP);
+  // Return out -= TMP.
+  __ Subu(out, out, TMP);
 
   __ Bind(&done);
 }