10 Commits

Author SHA1 Message Date
Craig Topper
db25f51e37 Revert "[DAGCombiner] Fold (mul (sra X, BW-1), Y) -> (neg (and (sra X, BW-1), Y))"
This reverts commit e8b3ffa532b8ebac5dcdf17bb91b47817382c14d.

The AMDGPU/mad_64_32.ll seems to fail on some of the build bots but
passes locally. I'm really confused.
2022-10-22 22:50:43 -07:00
Craig Topper
e8b3ffa532 [DAGCombiner] Fold (mul (sra X, BW-1), Y) -> (neg (and (sra X, BW-1), Y))
(sra X, BW-1) is either 0 or -1. So the multiply is a conditional
negate of Y.

This pattern shows up when type legalizing wide multiplies involving
a sign extended value.

Fixes PR57549.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D133399
2022-10-22 21:51:45 -07:00
Craig Topper
ac9209751a Revert "[DAGCombiner] Fold (mul (sra X, BW-1), Y) -> (neg (and (sra X, BW-1), Y))"
This reverts commit 0148df8157f05ecf3b1064508e6f012aefb87dad.

Getting a lit test failures on AMDGPU but I can't reproduce it so far.
Reverting to investigate.
2022-10-11 16:30:40 -07:00
Craig Topper
0148df8157 [DAGCombiner] Fold (mul (sra X, BW-1), Y) -> (neg (and (sra X, BW-1), Y))
(sra X, BW-1) is either 0 or -1. So the multiply is a conditional
negate of Y.

This pattern shows up when type legalizing wide multiplies involving
a sign extended value.

Fixes PR57549.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D133399
2022-10-11 16:20:55 -07:00
Kai Nacke
5403c59c60 [PPC] Opaque pointer migration, part 2.
The LIT test cases were migrated with the script provided by
Nikita Popov. Due to the size of the change it is split into
several parts.

Reviewed By: nemanja, nikic

Differential Revision: https://reviews.llvm.org/D135474
2022-10-11 17:24:06 +00:00
Craig Topper
e745f7c563 [LegalizeTypes] Improve ExpandIntRes_XMULO codegen.
The code previously used two BUILD_PAIRs to concatenate the two UMULO
results with 0s in the lower bits to match original VT. Then it created
an ADD and a UADDO with the original bit width. Each of those operations
need to be expanded since they have illegal types.

Since we put 0s in the lower bits before the ADD, the lower half of the
ADD result will be 0. So the lower half of the UADDO result is
solely determined by the other operand. Since the UADDO need to
be split in half, we don't really needd an operation for the lower
bits. Unfortunately, we don't see that in type legalization and end up
creating something more complicated and DAG combine or
lowering aren't always able to recover it.

This patch directly generates the narrower ADD and UADDO to avoid
needing to legalize them. Now only the MUL is done on the original
type.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D97440
2021-03-01 09:54:32 -08:00
Esme-Yi
29eb3dcfe6 [PowerPC] Materialize i64 constants by enumerated patterns.
Summary: Some constants can be handled with less instructions than our current results. And it seems our original approach is not very easy to extend. Therefore this patch proposes to materialize all 64-bit constants by enumerated patterns.
I traversed almost all constants to verified the functionality of these pattens. A traversed comparison of the number of instructions used by the original method and the new method has also been completed, where no degradation was caused by this patch. This patch also passed Bootstrap test and SPEC test.
Improvements of this patch are shown in llvm/test/CodeGen/PowerPC/constants-i64.ll

Reviewed By: steven.zhang, stefanp

Differential Revision: https://reviews.llvm.org/D92089
2020-12-21 05:21:07 +00:00
Jay Foad
62fd7f767c [MachineScheduler] Fix the TopDepth/BotHeightReduce latency heuristics
tryLatency compares two sched candidates. For the top zone it prefers
the one with lesser depth, but only if that depth is greater than the
total latency of the instructions we've already scheduled -- otherwise
its latency would be hidden and there would be no stall.

Unfortunately it only tests the depth of one of the candidates. This can
lead to situations where the TopDepthReduce heuristic does not kick in,
but a lower priority heuristic chooses the other candidate, whose depth
*is* greater than the already scheduled latency, which causes a stall.

The fix is to apply the heuristic if the depth of *either* candidate is
greater than the already scheduled latency.

All this also applies to the BotHeightReduce heuristic in the bottom
zone.

Differential Revision: https://reviews.llvm.org/D72392
2020-07-17 11:02:13 +01:00
Kang Zhang
513976df2e [PowerPC] Ignore implicit register operands for MCInst
Summary:
When doing the conversion: MachineInst -> MCInst, we should ignore the
implicit operands, it will expose more opportunity for InstiAlias.

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D77118
2020-04-16 16:22:43 +00:00
Nemanja Ivanovic
5fe2809447 [PowerPC] Don't assert on SELECT_CC with i1 type
When we try to select a SELECT_CC on Power9, we check if it can be matched to a
SETB instruction. In that function, we assert that the output type is i32/i64.
This is unnecessary as it is perfectly reasonable to have an i1 SELECT_CC.
Change that from an assert to an early exit condition.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=45448
2020-04-09 19:27:32 -05:00