Using the Registers Window

To display the Registers window

The Registers window displays register contents. If you keep the Registers window open as you step through your program, you can see register values change as your code executes. Values that have changed recently appear in red.

To reduce clutter, the Registers window organizes registers into groups. You can display or hide groups as you see fit. The Registers window displays SSE, SSE2, and 3DNow! registers in the following way:

3DNow! Registers

The debugger splits each MMX register into two 32-bit floats of the form MMnm, where n is the MMX register number, and m is zero or one for each half. 3DNow! registers are available on the AMD (Athlon) K6 and K7 processors.

SSE Registers

The debugger splits each XMM register into four 32-bit floats of the form XMMnm, where n is the XMM register number and m is 0-3 to denote which part of the register is used. These registers are available on Katmia (Pentium III) and WNI processors.

SSE2 Instructions Registers

The debugger splits each XMM register into two halves, both as integer and floating point. The notation is XMM followed by the register number, then D (for double, then L (low half) or H (high half). SSE2 integer registers (I registers) do not appear in the Registers window. To view I registers, enter the register name in the Watch window. These registers are available on WNI processors.

You can edit the value of a register in the Registers window. If you choose to display the register flags group, you can edit register flags. For Intel x86 processors, you can set the following register flags:

Register Window Flags

Flag Set Value  
Overflow O = 1  
Direction D = 1  
Interrupt I = 1  
Sign S = 1  
Zero Z = 1  
Auxiliary carry A = 1  
Parity P = 1  
Carry C = 1