For type v4i32/v8ii16/v16i8, do following transforms:
(vselect (setcc a, b, setugt), (sub a, b), (sub b, a)) -> (vabsd a, b)
(vselect (setcc a, b, setuge), (sub a, b), (sub b, a)) -> (vabsd a, b)
(vselect (setcc a, b, setult), (sub b, a), (sub a, b)) -> (vabsd a, b)
(vselect (setcc a, b, setule), (sub b, a), (sub a, b)) -> (vabsd a, b)
Differential Revision: https://reviews.llvm.org/D55812
llvm-svn: 349599
Power9 VABSDU* instructions can be exploited for some special vselect sequences.
Check in the orignal test case here, later the exploitation patch will update this
and reviewers can check the differences easily.
llvm-svn: 349446
Improve the current vec_abs support on P9, generate ISD::ABS node for vector types,
combine ABS node to VABSD node for some special cases to make use of P9 VABSD* insns,
do custom lowering to vsub(vneg later)+vmax if it has no combination opportunity.
Differential Revision: https://reviews.llvm.org/D54783
llvm-svn: 349437
Appended options -ppc-vsr-nums-as-vr and -ppc-asm-full-reg-names to get the
more descriptive output. Also removed useless function attributes.
llvm-svn: 349329
Vectorized loops with abs() returns incorrect results on POWER9. This patch fixes it.
For example the following code returns negative result if input values are negative though it sums up the absolute value of the inputs.
int vpx_satd_c(const int16_t *coeff, int length) {
int satd = 0;
for (int i = 0; i < length; ++i) satd += abs(coeff[i]);
return satd;
}
This problem causes test failures for libvpx.
For vector absolute and vector absolute difference on POWER9, LLVM generates VABSDUW (Vector Absolute Difference Unsigned Word) instruction or variants.
Since these instructions are for unsigned integers, we need adjustment for signed integers.
For abs(sub(a, b)), we generate VABSDUW(a+0x80000000, b+0x80000000). Otherwise, abs(sub(-1, 0)) returns 0xFFFFFFFF(=-1) instead of 1. For abs(a), we generate VABSDUW(a+0x80000000, 0x80000000).
Differential Revision: https://reviews.llvm.org/D45522
llvm-svn: 330497
Power 9 has instructions to do absolute difference (VABSDUB, VABSDUH, VABSDUW)
for byte, halfword and word. We should take advantage of these.
Differential Revision: https://reviews.llvm.org/D34684
llvm-svn: 309876
Kewen Lin