gcc and possibly many other programs use this reversed syntax, so
we're stuck with it.
- eg. `fsub %st(3),%st' results in st <- st - st(3) as expected, but
- `fsub %st,%st(3)' results in st(3) <- st - st(3), rather than
- the expected st(3) <- st(3) - st !
+ eg. `fsub %st(3),%st' results in st = st - st(3) as expected, but
+ `fsub %st,%st(3)' results in st(3) = st - st(3), rather than
+ the expected st(3) = st(3) - st
This happens with all the non-commutative arithmetic floating point
operations with two register operands, where the source register is
- %st, and destination register is %st(i). Look for FloatDR below. */
+ %st, and destination register is %st(i). See FloatDR below.
+
+ The affected opcode map is dceX, dcfX, deeX, defX. */
#ifndef UNIXWARE_COMPAT
/* Set non-zero for broken, compatible instructions. Set to zero for
#define sld_FP (sld_Suf|IgnoreSize)
#define sldx_FP (sldx_Suf|IgnoreSize)
#if UNIXWARE_COMPAT
+/* Someone forgot that the FloatR bit reverses the operation when not
+ equal to the FloatD bit. ie. Changing only FloatD results in the
+ destination being swapped *and* the direction being reversed. */
#define FloatDR FloatD
#else
#define FloatDR (FloatD|FloatR)