Modified: trunk/Source/_javascript_Core/ChangeLog (154206 => 154207)
--- trunk/Source/_javascript_Core/ChangeLog 2013-08-16 21:56:36 UTC (rev 154206)
+++ trunk/Source/_javascript_Core/ChangeLog 2013-08-16 23:34:21 UTC (rev 154207)
@@ -1,3 +1,23 @@
+2013-08-16 Benjamin Poulain <[email protected]>
+
+ [JSC] x86: improve code generation for xxxTest32
+ https://bugs.webkit.org/show_bug.cgi?id=119876
+
+ Reviewed by Geoffrey Garen.
+
+ Try to use testb whenever possible when testing for an immediate value.
+
+ When the input is an address and an offset, we can tweak the mask
+ and offset to be able to generate testb for any byte of the mask.
+
+ When the input is a register, we can use testb if we are only interested
+ in testing the low bits.
+
+ * assembler/MacroAssemblerX86Common.h:
+ (JSC::MacroAssemblerX86Common::branchTest32):
+ (JSC::MacroAssemblerX86Common::test32):
+ (JSC::MacroAssemblerX86Common::generateTest32):
+
2013-08-16 Mark Lam <[email protected]>
<https://bugs.webkit.org/show_bug.cgi?id=119913> Baseline JIT gives erroneous
Modified: trunk/Source/_javascript_Core/assembler/MacroAssemblerX86Common.h (154206 => 154207)
--- trunk/Source/_javascript_Core/assembler/MacroAssemblerX86Common.h 2013-08-16 21:56:36 UTC (rev 154206)
+++ trunk/Source/_javascript_Core/assembler/MacroAssemblerX86Common.h 2013-08-16 23:34:21 UTC (rev 154207)
@@ -1138,9 +1138,10 @@
Jump branchTest32(ResultCondition cond, RegisterID reg, TrustedImm32 mask = TrustedImm32(-1))
{
- // if we are only interested in the low seven bits, this can be tested with a testb
if (mask.m_value == -1)
m_assembler.testl_rr(reg, reg);
+ else if (!(mask.m_value & ~0xff))
+ m_assembler.testb_i8r(mask.m_value, reg);
else
m_assembler.testl_i32r(mask.m_value, reg);
return Jump(m_assembler.jCC(x86Condition(cond)));
@@ -1148,10 +1149,7 @@
Jump branchTest32(ResultCondition cond, Address address, TrustedImm32 mask = TrustedImm32(-1))
{
- if (mask.m_value == -1)
- m_assembler.cmpl_im(0, address.offset, address.base);
- else
- m_assembler.testl_i32m(mask.m_value, address.offset, address.base);
+ generateTest32(address, mask);
return Jump(m_assembler.jCC(x86Condition(cond)));
}
@@ -1419,10 +1417,7 @@
void test32(ResultCondition cond, Address address, TrustedImm32 mask, RegisterID dest)
{
- if (mask.m_value == -1)
- m_assembler.cmpl_im(0, address.offset, address.base);
- else
- m_assembler.testl_i32m(mask.m_value, address.offset, address.base);
+ generateTest32(address, mask);
set32(x86Condition(cond), dest);
}
@@ -1504,6 +1499,22 @@
// x86_64, and clients & subclasses of MacroAssembler should be using 'supportsFloatingPoint()'.
friend class MacroAssemblerX86;
+ ALWAYS_INLINE void generateTest32(Address address, TrustedImm32 mask = TrustedImm32(-1))
+ {
+ if (mask.m_value == -1)
+ m_assembler.cmpl_im(0, address.offset, address.base);
+ else if (!(mask.m_value & ~0xff))
+ m_assembler.testb_im(mask.m_value, address.offset, address.base);
+ else if (!(mask.m_value & ~0xff00))
+ m_assembler.testb_im(mask.m_value >> 8, address.offset + 1, address.base);
+ else if (!(mask.m_value & ~0xff0000))
+ m_assembler.testb_im(mask.m_value >> 16, address.offset + 2, address.base);
+ else if (!(mask.m_value & ~0xff000000))
+ m_assembler.testb_im(mask.m_value >> 24, address.offset + 3, address.base);
+ else
+ m_assembler.testl_i32m(mask.m_value, address.offset, address.base);
+ }
+
#if CPU(X86)
#if OS(MAC_OS_X)
