+ enum BranchTruncateType { BranchIfTruncateFailed, BranchIfTruncateSuccessful };
+ Jump branchTruncateDoubleToInt32(FPRegisterID src, RegisterID dest, BranchTruncateType branchType = BranchIfTruncateFailed)
+ {
+ // Convert into dest.
+ m_assembler.vcvt_floatingPointToSigned(fpTempRegisterAsSingle(), src);
+ m_assembler.vmov(dest, fpTempRegisterAsSingle());
+
+ // Calculate 2x dest. If the value potentially underflowed, it will have
+ // clamped to 0x80000000, so 2x dest is zero in this case. In the case of
+ // overflow the result will be equal to -2.
+ Jump underflow = branchAdd32(Zero, dest, dest, dataTempRegister);
+ Jump noOverflow = branch32(NotEqual, dataTempRegister, TrustedImm32(-2));
+
+ // For BranchIfTruncateSuccessful, we branch if 'noOverflow' jumps.
+ underflow.link(this);
+ if (branchType == BranchIfTruncateSuccessful)
+ return noOverflow;
+
+ // We'll reach the current point in the code on failure, so plant a
+ // jump here & link the success case.
+ Jump failure = jump();
+ noOverflow.link(this);
+ return failure;
+ }
+
+ // Result is undefined if the value is outside of the integer range.
+ void truncateDoubleToInt32(FPRegisterID src, RegisterID dest)
+ {
+ m_assembler.vcvt_floatingPointToSigned(fpTempRegisterAsSingle(), src);
+ m_assembler.vmov(dest, fpTempRegisterAsSingle());
+ }
+
+ void truncateDoubleToUint32(FPRegisterID src, RegisterID dest)
+ {
+ m_assembler.vcvt_floatingPointToUnsigned(fpTempRegisterAsSingle(), src);
+ m_assembler.vmov(dest, fpTempRegisterAsSingle());
+ }
+
+ // Convert '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, 0).
+ void branchConvertDoubleToInt32(FPRegisterID src, RegisterID dest, JumpList& failureCases, FPRegisterID, bool negZeroCheck = true)
+ {
+ m_assembler.vcvt_floatingPointToSigned(fpTempRegisterAsSingle(), src);
+ m_assembler.vmov(dest, fpTempRegisterAsSingle());
+
+ // Convert the integer result back to float & compare to the original value - if not equal or unordered (NaN) then jump.
+ m_assembler.vcvt_signedToFloatingPoint(fpTempRegister, fpTempRegisterAsSingle());
+ failureCases.append(branchDouble(DoubleNotEqualOrUnordered, src, fpTempRegister));
+
+ // If the result is zero, it might have been -0.0, and the double comparison won't catch this!
+ if (negZeroCheck)
+ failureCases.append(branchTest32(Zero, dest));
+ }
+
+ Jump branchDoubleNonZero(FPRegisterID reg, FPRegisterID)
projects / apple / javascriptcore.git / blobdiff