4 ms·

Visual studio C++ compiler is very comparable to the rest of them. I think the OP got screwed by cmake. While it technically supports Windows, the level of supp

Visual studio C++ compiler is very comparable to the rest of them. I think the OP got screwed by cmake. While it technically supports Windows, the level of support is not great. To make fast binaries with Visual C++, use Visual Studio to create and configure the project. The most important settings are following: • C/C++ / Code Generation / Enable Enhanced Instruction Set • C/C++ / Optimization / Whole Program Optimization • Linker / Optimization / Link Time Code Generation While it’s technically possible to set up the correct VC++ options with CMakeLists.txt, it’s relatively hard: need to detect VC++ compiler, and pass these weird command-line switches. Most cross-platform C++ libraries aren’t doing that.

blondin 4y ago
interesting! the builder is making the program slow? would be interesting to see the benchmark result using cl commands directly.
- tialaramex 4y ago
  Microsoft got where they did by prioritising extreme backward compatibility, hence the SimCity on Windows 95 story - SimCity has a bug, Windows 95 specifically works around the bug so now SimCity works on Windows 95. For ordinary end user software this is unabiguously good news, for a compiler it's more of a mixed bag.
  - pcdevils 4y ago
    The ADK used a lookup db to apply those fixes though; it wasn't a global fudge. Windows compatibility has probably been the main differentiator over the decades and every break (vista driver signing, dropping support for a bunch of scanners/printers, os quality issues) then 10 and even more so 11 making upgrading a mess of seemingly huge hardware replacement costs for next to no user/use gains, has caused uproar. Hell even xp was a mess; windows compatibility mode barely did what it suggested; but the intention was there.
TinkersW 4y ago
I told it to generate a VS solution to see what build settings it had applied.. and it is set up very poorly, not surprising performance is ass. This is release settings: intrinsics = off SIMD = off whole program optimizations = off link time code gen = off
jcranmer 4y ago
The latter two flags are roughly equivalent to `-flto` on gcc/clang, and it's not a fair comparison to enable it for VC++ but not gcc/clang. (It seems that you can set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON) to make cmake enable lto).
DannyBee 4y ago
Comparing lto vs not does make sense. You'd want to compare lto vs lto and not vs not. This is not vs not. It is a fair comparison in that sense
leni536 4y ago
AFAIK the fastfloat benchmark is a single translation unit anyway. Whole program optimization and LTO buys you nothing there. GCC and clang are both conservative with instruction set withou march option. I'm often disappointed by MSVC codegen when examining it in godbolt, I'm not surprised by the results here.

blondin 4y ago

interesting! the builder is making the program slow? would be interesting to see the benchmark result using cl commands directly.

tialaramex 4y ago
Microsoft got where they did by prioritising extreme backward compatibility, hence the SimCity on Windows 95 story - SimCity has a bug, Windows 95 specifically works around the bug so now SimCity works on Windows 95. For ordinary end user software this is unabiguously good news, for a compiler it's more of a mixed bag.
- pcdevils 4y ago
  The ADK used a lookup db to apply those fixes though; it wasn't a global fudge. Windows compatibility has probably been the main differentiator over the decades and every break (vista driver signing, dropping support for a bunch of scanners/printers, os quality issues) then 10 and even more so 11 making upgrading a mess of seemingly huge hardware replacement costs for next to no user/use gains, has caused uproar. Hell even xp was a mess; windows compatibility mode barely did what it suggested; but the intention was there.

TinkersW 4y ago

I told it to generate a VS solution to see what build settings it had applied.. and it is set up very poorly, not surprising performance is ass. This is release settings: intrinsics = off SIMD = off whole program optimizations = off link time code gen = off

jcranmer 4y ago

The latter two flags are roughly equivalent to `-flto` on gcc/clang, and it's not a fair comparison to enable it for VC++ but not gcc/clang. (It seems that you can set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON) to make cmake enable lto).

DannyBee 4y ago

Comparing lto vs not does make sense. You'd want to compare lto vs lto and not vs not. This is not vs not. It is a fair comparison in that sense

leni536 4y ago

AFAIK the fastfloat benchmark is a single translation unit anyway. Whole program optimization and LTO buys you nothing there. GCC and clang are both conservative with instruction set withou march option. I'm often disappointed by MSVC codegen when examining it in godbolt, I'm not surprised by the results here.