Displaying 1 result from an estimated 1 matches for "dspilling_ensues".
2014 Oct 13
2
[LLVMdev] Unexpected spilling of vector register during lane extraction on some x86_64 targets
...in the disassembly below),
local var 'rem' gets spilled and read back as scalars, depending on which
version of the integer lane accessor was used.
Output from clang 3.4 for target corei7-avx:
$ clang++ test.cpp -O3 -fstrict-aliasing -funroll-loops -ffast-math
-march=native -mtune=native -DSPILLING_ENSUES=0 /* no spilling */
$ objdump -dC --no-show-raw-insn ./a.out
...
00000000004004f0 <main>:
4004f0: vmovdqa 0x2004c8(%rip),%xmm0 # 6009c0 <x>
4004f8: vpsrld $0x17,%xmm0,%xmm0
4004fd: vpaddd 0x17b(%rip),%xmm0,%xmm0 # 400680
<__dso_handle+0x8>
400505: v...