[STDCXX-899] [MSVC] pow (double (x), double (int (y))) and pow (double (x), int (y)) returns sometimes the different results on 64-bit MSVC

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: External

Environment

64-bit MSVC

• Severity: Incorrect Behavior
• Assignee: Unassigned
• Reporter: Farid Zaripov
• Created: 29/Apr/08 17:58
• Updated: 29/Apr/08 17:58

Description

The 26.c.math test fails on 64-bit MSVC with the following assertions:

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-9.0, -8) = 2.32306e-08
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-9.0L, -8) = 2.32306e-08
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-9.0, -3) = -0.00137174, std::pow (-9.0, -3.0) = -0.00137174
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-9.0L, -3) = -0.00137174, std::pow (-9.0L, -3.0L) = -0.00137174
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-6.0, -9) = -9.9229e-08
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-6.0L, -9) = -9.9229e-08
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-6.0, -6) = 2.14335e-05
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-6.0L, -6) = 2.14335e-05
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-3.0, -9) = -5.08053e-05
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-3.0L, -9) = -5.08053e-05
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-3.0, -6) = 0.00137174, std::pow (-3.0, -6.0) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (-3.0L, -6) = 0.00137174, std::pow (-3.0L, -6.0L) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (3.0, -9) = 5.08053e-05
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (3.0L, -9) = 5.08053e-05
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (3.0, -6) = 0.00137174, std::pow (3.0, -6.0) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (3.0L, -6) = 0.00137174, std::pow (3.0L, -6.0L) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (6.0, -9) = 9.9229e-08
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (6.0L, -9) = 9.9229e-08
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (6.0, -6) = 2.14335e-05
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (6.0L, -6) = 2.14335e-05
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (9.0, -8) = 2.32306e-08
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (9.0L, -8) = 2.32306e-08
# CLAUSE: lib.c.math
# LINE: 240

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (9.0, -3) = 0.00137174, std::pow (9.0, -3.0) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 226

# ASSERTION (S7) (4 lines):
# TEXT: std::pow (9.0L, -3) = 0.00137174, std::pow (9.0L, -3.0L) = 0.00137174
# CLAUSE: lib.c.math
# LINE: 240

The printed resulting values are the same, but actually they differs in one/two least significant digits.

Since the problem in MSVC CRT, I suppose that the only way to get rid of these asserts is convert them to rw_warn() when _RWSTD_STRICT_ANSI is not #defined.