From f6cf2952ebda80eda64fd8ebb99801f8f43b993a Mon Sep 17 00:00:00 2001
From: Jacob Bramley <Jacob.Bramley@arm.com>
Date: Wed, 11 May 2011 15:16:22 +0100
Subject: [PATCH] Add absDouble to the MacroAssembler interface, and abstract
 the 'x & -x' trick away as it is an x86-specific optimization. [bug 655260]
 [r=bhackett]

---
 js/src/assembler/assembler/ARMAssembler.h            | 8 ++++++++
 js/src/assembler/assembler/MacroAssemblerARM.h       | 5 +++++
 js/src/assembler/assembler/MacroAssemblerX86Common.h | 9 +++++++++
 js/src/methodjit/FastBuiltins.cpp                    | 5 +----
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/js/src/assembler/assembler/ARMAssembler.h b/js/src/assembler/assembler/ARMAssembler.h
index d60a2756c98..09d21adcb73 100644
--- a/js/src/assembler/assembler/ARMAssembler.h
+++ b/js/src/assembler/assembler/ARMAssembler.h
@@ -190,6 +190,7 @@ namespace JSC {
             FCPYD = 0x0eb00b40,
             FADDD = 0x0e300b00,
             FNEGD = 0x0eb10b40,
+            FABSD = 0x0eb00bc0,
             FDIVD = 0x0e800b00,
             FSUBD = 0x0e300b40,
             FMULD = 0x0e200b00,
@@ -548,6 +549,13 @@ namespace JSC {
             m_buffer.putInt(static_cast<ARMWord>(cc) | FNEGD | DD(dd) | DM(dm));
         }
 
+        void fabsd_r(int dd, int dm, Condition cc = AL)
+        {
+            js::JaegerSpew(js::JSpew_Insns,
+                    IPFX   "%-15s %s, %s, %s, %s\n", MAYBE_PAD, "fabsd", nameFpRegD(dd), nameFpRegD(dm));
+            m_buffer.putInt(static_cast<ARMWord>(cc) | FABSD | DD(dd) | DM(dm));
+        }
+
         void fdivd_r(int dd, int dn, int dm, Condition cc = AL)
         {
             js::JaegerSpew(js::JSpew_Insns,
diff --git a/js/src/assembler/assembler/MacroAssemblerARM.h b/js/src/assembler/assembler/MacroAssemblerARM.h
index 7413411f450..47b3b6c14b4 100644
--- a/js/src/assembler/assembler/MacroAssemblerARM.h
+++ b/js/src/assembler/assembler/MacroAssemblerARM.h
@@ -1037,6 +1037,11 @@ public:
         m_assembler.fnegd_r(dest, src);
     }
 
+    void absDouble(FPRegisterID src, FPRegisterID dest)
+    {
+        m_assembler.fabsd_r(dest, src);
+    }
+
     void sqrtDouble(FPRegisterID src, FPRegisterID dest)
     {
         m_assembler.fsqrtd_r(dest, src);
diff --git a/js/src/assembler/assembler/MacroAssemblerX86Common.h b/js/src/assembler/assembler/MacroAssemblerX86Common.h
index 5ba34a97a08..ee4cc310879 100644
--- a/js/src/assembler/assembler/MacroAssemblerX86Common.h
+++ b/js/src/assembler/assembler/MacroAssemblerX86Common.h
@@ -639,6 +639,15 @@ public:
         m_assembler.andpd_rr(src, dest);
     }
 
+    void absDouble(FPRegisterID src, FPRegisterID dest)
+    {
+        ASSERT(isSSE2Present());
+        /* Compile abs(x) as x & -x. */
+        zeroDouble(dest);
+        subDouble(src, dest);
+        andDouble(src, dest);
+    }
+
     void convertInt32ToDouble(RegisterID src, FPRegisterID dest)
     {
         ASSERT(isSSE2Present());
diff --git a/js/src/methodjit/FastBuiltins.cpp b/js/src/methodjit/FastBuiltins.cpp
index 3f34ee9229e..3c23460fafb 100644
--- a/js/src/methodjit/FastBuiltins.cpp
+++ b/js/src/methodjit/FastBuiltins.cpp
@@ -94,10 +94,7 @@ mjit::Compiler::compileMathAbsDouble(FrameEntry *arg)
     MaybeJump notNumber = loadDouble(arg, &fpReg, &allocate);
     JS_ASSERT(!notNumber.isSet());
 
-    /* Compile abs(x) as x & -x. */
-    masm.zeroDouble(fpResultReg);
-    masm.subDouble(fpReg, fpResultReg);
-    masm.andDouble(fpReg, fpResultReg);
+    masm.absDouble(fpReg, fpResultReg);
 
     if (allocate)
         frame.freeReg(fpReg);