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Report From: Delphi-BCB/Compiler/Delphi/BASM [ Add a report in this area ]

Report #: 87610

Status: Open

BASM DD and DQ do not handle floating point values correctly

Project: Delphi

Build #: 14.0.3539.24502

Version: 14.0

Submitted By: Philipp S

Report Type: Basic functionality failure

Date Reported: 8/28/2010 2:19:42 PM

Severity: Serious / Highly visible problem

Last Updated: 3/20/2012 2:24:39 AM

Platform: All platforms

Internal Tracking #: 280216

Resolution: None (Resolution Comments)

Resolved in Build: : None

Duplicate of: None

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Description

DD and DQ are used to declare 32-bit/DWORD and 64-bit/QWORD-sized data, respectively. BASM allows (u)int32 and (u)int64 data to be declared correctly: However, DD and DQ do not handle the declaration of 32-bit SINGLE-precision floating-point and 64-bit DOUBLE-precision floating-point values correctly.

Steps to Reproduce:

Inspect the code generated for the following instructions.
Expected: 0.5 and 1/2 should be treated as single values after DD and double values after DQ
Observed: 0.5 and 1/2 are treated as (different!) integer values

asm
      jmp @x
      @OneHalfDW1:
         dd 0.5   // actually, the compiler treats this as 05h integer
      @OneHalfDW2:
         dd 1/2   // actually, the compiler treats this as 00h integer
      @OneHalfDQ1:
         dq 0.5   // actually, the compiler treats this as 05h integer
      @OneHalfDQ2:
         dq 1/2   // actually, the compiler treats this as 00h integer
      @x:
        movss xmm0, dword ptr @OneHalfDW1
        movss xmm1, dword ptr @OneHalfDW2
        movsd xmm2, qword ptr @OneHalfDQ1
        movsd xmm3, qword ptr @OneHalfDQ2
        int 3 // inspect values in xmm0 - xmm3 in FPU view, and also the data inserted for the DDs and DQs
end;

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