Re: [PATCH] target/i386: reimplement f2xm1 using floatx80 operations

2020-06-12 Thread Paolo Bonzini
On 12/06/20 01:45, Joseph Myers wrote: > The x87 f2xm1 emulation is currently based around conversion to > double. This is inherently unsuitable for a good emulation of any > floatx80 operation, even before considering that it is a particularly > naive implementation using double (computing with

[PATCH] target/i386: reimplement f2xm1 using floatx80 operations

2020-06-11 Thread Joseph Myers
The x87 f2xm1 emulation is currently based around conversion to double. This is inherently unsuitable for a good emulation of any floatx80 operation, even before considering that it is a particularly naive implementation using double (computing with pow and then subtracting 1 rather than