cpuid build error on windows bots

kiwifig / libyuv

Automatically exported from code.google.com/p/libyuv

BSD 3-Clause "New" or "Revised" License

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source/cpu_id.cc:290:7: error: variable 'cpu_info' is used uninitialized 
whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]

  if (TestEnv("LIBYUV_DISABLE_ASM")) {

      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

source/cpu_id.cc:293:15: note: uninitialized use occurs here

  cpu_info_ = cpu_info;

              ^~~~~~~~

source/cpu_id.cc:290:3: note: remove the 'if' if its condition is always true

  if (TestEnv("LIBYUV_DISABLE_ASM")) {

  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

source/cpu_id.cc:200:15: note: initialize the variable 'cpu_info' to silence 
this warning

  int cpu_info;

              ^

               = 0

1 error generated.

Original issue reported on code.google.com by fbarch...@chromium.org on 22 Oct 2015 at 9:39

Switching to zero saves a byte per function call saves 1 byte per call Was 00000074: A1 00 00 00 00 mov eax,dword ptr [_cpu_info_] 00000079: 83 F8 01 cmp eax,1 0000007C: 75 08 jne 00000086 0000007E: E8 00 00 00 00 call _InitCpuFlags 00000086: A8 40 test al,40h 00000088: 74 21 je 000000AB Now 00000074: A1 00 00 00 00 mov eax,dword ptr [_cpu_info_] 00000079: 85 C0 test eax,eax 0000007B: 75 05 jne 00000082 0000007D: E8 00 00 00 00 call _InitCpuFlags 00000082: A8 40 test al,40h 00000084: 75 0C jne 00000092

kiwifig / libyuv

cpuid build error on windows bots #512