Prevent deopt on double value assignment to typed arrays

src/arm/stub-cache-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3908 matching lines @@
         __ vldr(d0, r5, HeapNumber::kValueOffset);
         __ add(r5, r3, Operand(r4, LSL, 2));
         __ vcvt_f32_f64(s0, d0);
         __ vstr(s0, r5, 0);
       } else if (array_type == kExternalDoubleArray) {
         __ sub(r5, r0, Operand(kHeapObjectTag));
         __ vldr(d0, r5, HeapNumber::kValueOffset);
         __ add(r5, r3, Operand(r4, LSL, 3));
         __ vstr(d0, r5, 0);
       } else {
-        // Need to perform float-to-int conversion.
-        // Test for NaN or infinity (both give zero).
-        __ ldr(r6, FieldMemOperand(value, HeapNumber::kExponentOffset));
-
         // Hoisted load.  vldr requires offset to be a multiple of 4 so we can
         // not include -kHeapObjectTag into it.
         __ sub(r5, value, Operand(kHeapObjectTag));
         __ vldr(d0, r5, HeapNumber::kValueOffset);
 
-        __ Sbfx(r6, r6, HeapNumber::kExponentShift, HeapNumber::kExponentBits);
-        // NaNs and Infinities have all-one exponents so they sign extend to -1.
-        __ cmp(r6, Operand(-1));
-        __ mov(r5, Operand(0), LeaveCC, eq);
-
-        // Not infinity or NaN simply convert to int.
-        if (IsElementTypeSigned(array_type)) {
-          __ vcvt_s32_f64(s0, d0, kDefaultRoundToZero, ne);
-        } else {
-          __ vcvt_u32_f64(s0, d0, kDefaultRoundToZero, ne);
-        }
-        __ vmov(r5, s0, ne);
+        __ EmitECMATruncate(r5,

[Kevin Millikin (Chromium), 2011/05/26 07:53:37]

Might as well put the args all on the same line.

[danno, 2011/06/01 13:14:41]

Done.

+                            d0,
+                            s2,
+                            r6,
+                            r7,
+                            r9);
 
         switch (array_type) {
           case kExternalByteArray:
           case kExternalUnsignedByteArray:
             __ strb(r5, MemOperand(r3, r4, LSL, 0));
             break;
           case kExternalShortArray:
           case kExternalUnsignedShortArray:
             __ strh(r5, MemOperand(r3, r4, LSL, 1));
             break;
@@ skipping 274 matching lines @@
       masm->isolate()->builtins()->KeyedStoreIC_MissForceGeneric();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM