search for: mmx_movd64

...word ptr [rax],ecx Note the last movq. What was probably intended to be generated was "movd ecx, mm0". LLVM mistakenly sets the 'wide' bit of the REX prefix to 1, turning movd into movq. Also, reg and r/m encoding has been swapped. I have not found a fix for this yet, but the MMX_MOVD64* definitions and patterns looks suspicious. Note that on x86-32 it produces correct code (though not optimal either; it doesn't use movd). Also, notice that the last two instructions above should ideally just be a single movd to memory, instead of first writing to a GP register. In the...

...o reproduce it: [snip > Note the last movq. What was probably intended to be generated was “movd > ecx, mm0”. LLVM mistakenly sets the ‘wide’ bit of the REX prefix to 1, > turning movd into movq. Also, reg and r/m encoding has been swapped. I have > not found a fix for this yet, but the MMX_MOVD64* definitions and patterns > looks suspicious. Thanks for the testcase; fixed in r75142. > Note that on x86-32 it produces correct code (though not optimal either; it > doesn’t use movd). Also, notice that the last two instructions above should > ideally just be a single movd to memory...