I have the following code which I compiled with g++ 6.1 on windows using the MinGW compiler.  unsigned char test_uc[8] = {0, 0xaa, 0xbb, 0xcc, 0x11, 0x22, 0x33, 0x44};  uint64_t* p64 = (uint64_t*)test_uc; __m256i res = _mm256_cvtepu8_epi32 (_mm_cvtsi64_si128(*p64)); uint32_t* u32 = (uint32_t*)&amp;res; for(int i = 0; i &lt; 8; i++)     printf("%d.0x%x\n", i, u32[i]);   When I run the program with optimization level -O1, I get the expected output as shown below.  0.0x0 1.0xaa 2.0xbb 3.0xcc 4.0x11 5.0x22 6.0x33 7.0x44   However, if I switch to optimization level -O3, I get this strange output.  0.0x0 1.0x0 2.0x0 3.0x0 4.0x8 5.0x0 6.0x41027f 7.0x0   What is going on here?
When asking about , people sometimes refer to the strict aliasing rule. What are they talking about?
Time Dilation When In Orbit When I have my external monitor hooked up, I access it by mousing off the left hand side of my Macbook display. Can I switch this so that I can access the external by mousing off to the right of My Macbook display?   The reason I ask, is my monitor is on the right side of my macbook, and it's unintuitive to mouse left to get to a screen on the right. if $A$ subset of $B$ then $P(B)-P(A)=P(B\setminus A)\ge 0$ Let $P$ be a probability measure on $(\Omega, \mathscr{F})$, If $a,b,\in\mathscr{F}$ and $A\subset B$, then $P(B)-P(A)=P(B\setminus A)\ge 0$.  So far I have:  $A\subset B \implies B\setminus A = B\cap A^c = \emptyset$ as $A$ and $B^c$ are disjoint. Since $A\cup (B\setminus A)=A\cup (B\cap A^c)=(A\cup B)\cap (A\cup A^c)=B\cap\Omega = B$  Then for $A,B\in \mathscr{F}\implies P(A\cup (B\setminus A))=P(A)+P(B\setminus A) = P(B)$ by countable additivity.  Rearranging, $P(B)-P(A)=P(B\setminus A) \ge 0$. How much money do I need to show as proof of support when applying for a UK Standard Visitor visa? I am an Indian citizen studying in Italy on an Italian visa that expires 19 November, 2015. I have permesso di soggiorno. I want to visit the United Kingdom for my vacations for a week during March. I know the procedures already, however I am a little bit confused about the amount that I must show as a proof of support with my bank statements. I will stay for a week with my friends who are also students in Italy and will be in London for 5 days. What would be the amount in Euros that I need to show for my visit to UK? If I have a Java source file (*.java) or a class file (*.class), how can I convert it to a .exe file?  I also need an installer for my program. How to concatenate items in a list to a single string? Confidence Interval Calculation I have temperature data of July 1991 to 2007, and wants to find the Confidence Interval at 95%, which distribution is best fit the data, Z or T. Please give me reason also.    minTemp = 14.4444, maxTemp = 38.3333, SizeofData = 527, (17 years) hist(July, 20), histfit(July, 20); Why and how can you hear explosions in space in Star Wars? Considering that sound can't travel through vacuum. Can new wall go over tile floor? Looking at moving my laundry upstairs, and the right answer is to combine two adjacent closets to get the width and move one of their walls a foot or two into the kitchen to get the depth.  The kitchen floor is 10-inch-square tiles. It would be sort of nice if that continued on into the laundry closet. I do have a full bundle of spare tiles in the basement.   Question: Could/should I plan on the new wall coming in on top of the existing tiles (presumably having to drill to secure the footer without shattering them), or should I plan on removing the ones under the footer and fitting cut pieces back in afterward? Invoking JavaScript code in an iframe from the parent page Basically, I have an iframe embedded in a page and the iframe has some  routines I need to invoke from the parent page.  Now the opposite is quite simple as you only need to call parent.functionName(), but unfortunately, I need exactly the opposite of that.  Please note that my problem is not changing the source  of the iframe, but invoking a function defined in the iframe. What is a proper way to clean a 35mm negative film stripe before scanning?   What chemicals can remove fingerprints, dust that does not come off by blowing, or strains of glue? What type of cloth does minimal damage when rubbing off dirt? sed - replace string with file contents I have two files: file1 and file2.  file1 has the following contents:  ---   host: "localhost"   port: 3000   reporter_type: "zookeeper"   zk_hosts:      - "localhost:2181"   file2 contains an IP address (1.1.1.1)  What I want to do is replace localhost with 1.1.1.1, so that the end result is:  ---   host: "1.1.1.1"   port: 3000   reporter_type: "zookeeper"   zk_hosts:      - "1.1.1.1:2181"   I have tried:  sed -i -e "/localhost/r file2" -e "/localhost/d" file1 sed '/localhost/r file2' file1 |sed '/localhost/d' sed -e '/localhost/r file2' -e "s///" file1   But I either get the whole line replaced, or the IP going to the line after the one I need to modify. Does photon have size measurement because of its particle nature Does photon have size measurement because of its particle nature like electron's 3.86*10^-13m etc.. How do I determine the size of my array in C?   That is, the number of elements the array can hold? I have continuous problems of network dropping connections on wifi with ubuntu 16.04, I have an ASUS R510J, this is my network card:  ##### lspci #############################  03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter [10ec:8821]         Subsystem: AzureWave RTL8821AE 802.11ac PCIe Wireless Network Adapter [1a3b:2161]         Kernel driver in use: rtl8821ae  04:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 12)         Subsystem: ASUSTeK Computer Inc. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [1043:200f]         Kernel driver in use: r8169   sudo service network-manager restart doesnt's help, as I never regain internet connection after it drops, and I have to restart the PC. On Ethernet cable I have no problem.  What do you think is the issue? drivers?  thank you Let $P\in\mathbb{R}[X]$ be a positive polynomial.  I want to show that there exists $A,B\in\mathbb{R}[X]$ so that $P=A^2+B^2$    $\displaystyle P=a\prod_{k=0}^q(x-a_k)\prod_{k=0}^{2p}(x-b_k)=a\prod_{k=0}^q(x-a_k)\prod_{k=0}^p(x^2-2\Re(b_k)+|b_k|^2)$ where $a$ is the leading coefficient, $a_k$ are the real rooks, $b_k$ are the complex roots.  What can i do now ? I know that the identity $(a^2+b^2)(c^2+d^2)=(ac-bd)^2+(ad+bc)^2$ should come in handy, but I can't figure out :  1) How to show that the product real roots is a square  2) How to use the above identity for the complex roots.  If I can solve those two points, then I can solve the problem. High p-values for logistic regression variable that perfectly separates? I'm using R to run some logistic regression. My variables were continuous, but I used cut to bucket the data. Some particular buckets for these variables always result in dependent variable being equal to 1. As expcted, the coefficient estimate for this bucket is very high, but the p-value is also high. There are about ~90 observations in either these buckets, and around 800 total observations, so I don't think it's a problem of sample size. Also, this variable should not be related to other variables, which would naturally reduce their p-values.  Are there any other plausible explanations for the high p-value?  Example:  myData &lt;- read.csv("application.csv", header = TRUE) myData$FICO &lt;- cut(myData$FICO, c(0, 660, 680, 700, 720, 740, 780, Inf), right = FALSE) myData$CLTV &lt;- cut(myData$CLTV, c(0, 70, 80, 90, 95, 100, 125, Inf), right = FALSE) fit &lt;- glm(Denied ~ CLTV + FICO, data = myData, family=binomial())   Results are something like this:  Deviance Residuals:       Min        1Q    Median        3Q       Max   -1.53831  -0.77944  -0.62487   0.00027   2.09771    Coefficients:                 Estimate Std. Error z value Pr(&gt;|z|)     (Intercept)     -1.33630    0.23250  -5.747 9.06e-09 *** CLTV(70,80]     -0.54961    0.34864  -1.576 0.114930     CLTV(80,90]     -0.51413    0.31230  -1.646 0.099715 .   CLTV(90,95]     -0.74648    0.37221  -2.006 0.044904 *   CLTV(95,100]     0.38370    0.37709   1.018 0.308906     CLTV(100,125]   -0.01554    0.25187  -0.062 0.950792     CLTV(125,Inf]   18.49557  443.55550   0.042 0.966739     FICO[0,660)     19.64884 3956.18034   0.005 0.996037     FICO[660,680)    1.77008    0.47653   3.715 0.000204 *** FICO[680,700)    0.98575    0.30859   3.194 0.001402 **  FICO[700,720)    1.31767    0.27166   4.850 1.23e-06 *** FICO[720,740)    0.62720    0.29819   2.103 0.035434 *   FICO[740,780)    0.31605    0.23369   1.352 0.176236     --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  (Dispersion parameter for binomial family taken to be 1)      Null deviance: 1037.43  on 810  degrees of freedom Residual deviance:  803.88  on 798  degrees of freedom AIC: 829.88  Number of Fisher Scoring iterations: 16   FICO in the range [0, 660) and CLTV in the range (125, Inf] indeed always results in Denial = 1, so their coefficients are very large, but why are they also "insignificant"? Disable output buffering Is output buffering enabled by default in Python's interpreter for sys.stdout?  If the answer is positive, what are all the ways to disable it?  Suggestions so far:   Use the -u command line switch Wrap sys.stdout in an object that flushes after every write Set PYTHONUNBUFFERED env var sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)   Is there any other way to set some global flag in sys/sys.stdout programmatically during execution? Is 512 bits a more secure hashing than 256 bits? I unintentionally and stupidly wiped my Clash of Clans game data. I went to Application Manager on my Android and clicked 'Clear data'. (I used this for fixes before and it never started a new game.)   Now, my level 60 or so base has been wiped as if was to start a new game. Have I doomed myself to starting again or is there a way in which I can retrieve my old game save? Maybe by contacting Supercell? I have a snapshot of my base.