On 10/28/2016 03:43 PM, Segher Boessenkool wrote:
On Fri, Oct 28, 2016 at 01:18:19PM +0200, Bernd Schmidt wrote:
In this PR, we manage to simplify the code down to
(lt (and (reg) (signbit)) (const 0))
simplify_comparison then calls make_compound_operation on the AND
expression, and that turns it into a ZERO_EXTRACT of a single bit,
changing the meaning of the comparison.
The problem is a special case we have for comparisons in
make_compound_operation, it thinks it should convert single-bit ANDs
into such extractions. But this is only valid if the bit isn't the sign
bit, or if we're testing for equality with zero.
The following patch was bootstrapped and tested on x86_64-linux. Ok?
Okay, thanks!
Branches too?
Bernd
