commit 4f9ccebdf242bf5b20e392df62966e52db2741d8
author commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Wed Sep 07 02:00:16 2011 +0000
committer commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Wed Sep 07 02:00:16 2011 +0000
tree 922add78f7005bdc41f6e3f6e92af87a98fe5b6c
parent 5c6cdf8607fe6587145a06532af12eceb158c58a

Source/JavaScriptCore: https://bugs.webkit.org/show_bug.cgi?id=67486
This reverts r65993 which gives wrong results for rshift
in some corner cases (see the test).

Patch by Yong Li <yoli@rim.com> on 2011-09-06
Reviewed by Gavin Barraclough.

New test: fast/js/floating-point-truncate-rshift.html

* assembler/ARMAssembler.h:
* assembler/MacroAssemblerARM.h:
(JSC::MacroAssemblerARM::supportsFloatingPointTruncate):
(JSC::MacroAssemblerARM::branchTruncateDoubleToInt32):

LayoutTests: https://bugs.webkit.org/show_bug.cgi?id=67486
Add a test case for branchTruncateDoubleToInt32() which is
used in right shift optimization when the assembler
"supportsFloatingPointTruncate".

Patch by Yong Li <yoli@rim.com> on 2011-09-06
Reviewed by Gavin Barraclough.

* fast/js/floating-point-truncate-rshift-expected.txt: Added.
* fast/js/floating-point-truncate-rshift.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@94622 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/JavaScriptCore/assembler/MacroAssemblerARM.h

diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerARM.h b/Source/JavaScriptCore/assembler/MacroAssemblerARM.h
index 7210ac2..8cf3808 100644
--- a/Source/JavaScriptCore/assembler/MacroAssemblerARM.h
+++ b/Source/JavaScriptCore/assembler/MacroAssemblerARM.h
@@ -787,7 +787,7 @@
 
     bool supportsFloatingPointTruncate() const
     {
-        return s_isVFPPresent;
+        return false;
     }
 
     bool supportsFloatingPointSqrt() const
@@ -902,17 +902,13 @@
     // Truncates 'src' to an integer, and places the resulting 'dest'.
     // If the result is not representable as a 32 bit value, branch.
     // May also branch for some values that are representable in 32 bits
-    // (specifically, in this case, INT_MIN and INT_MAX).
+    // (specifically, in this case, INT_MIN).
     Jump branchTruncateDoubleToInt32(FPRegisterID src, RegisterID dest)
     {
-        m_assembler.vcvtr_s32_f64_r(ARMRegisters::SD0 << 1, src);
-        // If VCVTR.S32.F64 can't fit the result into a 32-bit
-        // integer, it saturates at INT_MAX or INT_MIN. Testing this is
-        // probably quicker than testing FPSCR for exception.
-        m_assembler.vmov_arm_r(dest, ARMRegisters::SD0 << 1);
-        m_assembler.sub_r(ARMRegisters::S0, dest, ARMAssembler::getOp2(0x80000000));
-        m_assembler.cmn_r(ARMRegisters::S0, ARMAssembler::getOp2(1), ARMCondition(NotEqual));
-        return Jump(m_assembler.jmp(ARMCondition(Equal)));
+        UNUSED_PARAM(src);
+        UNUSED_PARAM(dest);
+        ASSERT_NOT_REACHED();
+        return jump();
     }
 
     // Convert 'src' to an integer, and places the resulting 'dest'.