In combineOrCmpEqZeroToCtlzSrl, replace "getConstantOperand == 0" by "isNullConstant" to account for floating point constants.
Differential Revision: https://reviews.llvm.org/D29756
llvm-svn: 294588
Summary:
This patch enables the following
1. AMD family 17h architecture using "znver1" tune flag (-march, -mcpu).
2. ISAs that are enabled for "znver1" architecture.
3. Checks ADX isa from cpuid to identify "znver1" flag when -march=native is used.
4. ISAs FMA4, XOP are disabled as they are dropped from amdfam17.
5. For the time being, it uses the btver2 scheduler model.
6. Test file is updated to check this flag.
This item is linked to clang review item https://reviews.llvm.org/D28018
Patch by Ganesh Gopalasubramanian
Reviewers: RKSimon, craig.topper
Subscribers: vprasad, RKSimon, ashutosh.nema, llvm-commits
Differential Revision: https://reviews.llvm.org/D28017
llvm-svn: 291543
This change adds transformations such as:
zext(or(setcc(eq, (cmp x, 0)), setcc(eq, (cmp y, 0))))
To:
srl(or(ctlz(x), ctlz(y)), log2(bitsize(x))
This optimisation is beneficial on Jaguar architecture only, where lzcnt has a good reciprocal throughput.
Other architectures such as Intel's Haswell/Broadwell or AMD's Bulldozer/PileDriver do not benefit from it.
For this reason the change also adds a "HasFastLZCNT" feature which gets enabled for Jaguar.
Differential Revision: https://reviews.llvm.org/D23446
llvm-svn: 284248
Pierre Gousseau