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Date: Thu, 01 Jan 2015 00:00:00 -0000
Message-ID: <CACXZuxcrz32gfH=PEoiJ_w7ijpFX5Y_x5+-_NETVgGHKnxioCA@mail.gmail.com>
Subject: Weird problem
From: Dibyendu Majumdar <mobile@majumdar.org.uk>
To: jit@gcc.gnu.org
Content-Type: text/plain; charset=UTF-8
X-SW-Source: 2015-q2/txt/msg00131.txt.bz2

Hi Dave,

I am trying to debug a problem I am having with one piece of code.

The generated code (snippet) is shown below:

  double OP_RAVI_TOFLT_n_2_8;
  bool comparison_0_12;
  comparison_0_12 = luaV_tonumber_ (&base[(int)0],
&OP_RAVI_TOFLT_n_2_8) == (int)0;
  if (comparison_0_12) goto OP_RAVI_TOFLT_if_conversion_failed_2_13;
else goto OP_RAVI_TOFLT_if_conversion_ok_2_14;

OP_RAVI_TOFLT_if_conversion_ok_2_14:
  (void)printf ("number ok = %f\
", OP_RAVI_TOFLT_n_2_8);


The printf output says that value of OP_RAVI_TOFLT_n_2_8 is 0.0.
Yet the called function luaV_tonumber_() set this to a different value:

Output from luaV_tonumber_():

set *0x7ffe1bb8d298 to 5.600000

Output from JIT code above:

number ok = 0.000000

>From the dump it seems that the address of the local variable
OP_RAVI_TOFLT_n_2_8 is being passed to the function. And yet the value
of the variable is its original value which was 0.0.

Any tips on what I should be looking for?

Thanks and Regards
Dibyendu