#13629: sqrt should use machine instruction on x86_64 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler (NCG) | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #13570 | Differential Rev(s): Phab:D3508 Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): It's made in the native code generator, `genCCall` in `compiler/nativeGen/X86/CodeGen.hs`. While we use the `fsin` instruction on i386, we don't on x86_64 (and i386 with `-msse2`). See Phab:D3508 for a quick attempt at fixing the `sqrt` situation. In the case of trigonometric functions I'm afraid we have little choice but to fall back on `libm` since SSE provides no trig instructions. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13629#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler