[PATCH] D90113: [DAGCombiner] Fold BinOp into Select containing identity constant

[Layton Kifer via Phabricator via llvm-commits]

laytonio created this revision.
laytonio added reviewers: craig.topper, lebedev.ri, spatel, RKSimon.
Herald added subscribers: llvm-commits, ecnelises, kerbowa, pengfei, asbirlea, atanasyan, jrtc27, kbarton, hiraditya, nhaehnle, jvesely, nemanjai, sdardis.
Herald added a project: LLVM.
laytonio requested review of this revision.

To prevent materializing unneeded identity constants, and to avoid unnecessary arithmetic in branches that where the value wouldn't be modified, add folds for the following:

(add x, (select cc, 0, cf)) -> (select cc, x, (add x, cf))
(or x, (select cc, 0, cf)) -> (select cc, x, (or x, cf))
(xor x, (select cc, 0, cf)) -> (select cc, x, (xor x, cf))
(sub x, (select cc, 0, cf)) -> (select cc, x, (sub x, cf))
(shl x, (select cc, 0, cf)) -> (select cc, x, (shl x, cf))
(lshr x, (select cc, 0, cf)) -> (select cc, x, (lshr x, cf))
(ashr x, (select cc, 0, cf)) -> (select cc, x, (ashr x, cf))
(mul x, (select cc, 1, cf)) -> (select cc, x, (mul x, cf))
(sdiv x, (select cc, 1, cf)) -> (select cc, x, (sdiv x, cf))
(udiv x, (select cc, 1, cf)) -> (select cc, x, (udiv x, cf))
(and x, (select cc, -1, cf)) -> (select cc, x, (and x, cf))

Fixes select cases of PR47922


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D90113

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/AArch64/half.ll
  llvm/test/CodeGen/AArch64/midpoint-int.ll
  llvm/test/CodeGen/AArch64/use-cr-result-of-dom-icmp-st.ll
  llvm/test/CodeGen/AMDGPU/amdgpu-codegenprepare-idiv.ll
  llvm/test/CodeGen/AMDGPU/bypass-div.ll
  llvm/test/CodeGen/AMDGPU/idiv-licm.ll
  llvm/test/CodeGen/AMDGPU/sdiv.ll
  llvm/test/CodeGen/AMDGPU/sdiv64.ll
  llvm/test/CodeGen/AMDGPU/srem64.ll
  llvm/test/CodeGen/AMDGPU/udiv64.ll
  llvm/test/CodeGen/AMDGPU/urem64.ll
  llvm/test/CodeGen/Mips/funnel-shift-rot.ll
  llvm/test/CodeGen/Mips/funnel-shift.ll
  llvm/test/CodeGen/Mips/llvm-ir/ashr.ll
  llvm/test/CodeGen/Mips/llvm-ir/lshr.ll
  llvm/test/CodeGen/Mips/llvm-ir/shl.ll
  llvm/test/CodeGen/PowerPC/cmpb-ppc32.ll
  llvm/test/CodeGen/PowerPC/cmpb.ll
  llvm/test/CodeGen/PowerPC/combine_ext_trunc.ll
  llvm/test/CodeGen/PowerPC/fp-strict-conv-f128.ll
  llvm/test/CodeGen/PowerPC/noPermuteFormasking.ll
  llvm/test/CodeGen/PowerPC/nofpexcept.ll
  llvm/test/CodeGen/PowerPC/ppcf128-constrained-fp-intrinsics.ll
  llvm/test/CodeGen/PowerPC/rlwimi-and.ll
  llvm/test/CodeGen/PowerPC/use-cr-result-of-dom-icmp-st.ll
  llvm/test/CodeGen/SystemZ/subregliveness-04.ll
  llvm/test/CodeGen/Thumb2/LowOverheadLoops/predicated-liveout-unknown-lanes.ll
  llvm/test/CodeGen/X86/avx-select.ll
  llvm/test/CodeGen/X86/avx512-select.ll
  llvm/test/CodeGen/X86/binop-identity.ll
  llvm/test/CodeGen/X86/bool-simplify.ll
  llvm/test/CodeGen/X86/bool-vector.ll
  llvm/test/CodeGen/X86/fp-cvt.ll
  llvm/test/CodeGen/X86/fp-intrinsics-flags.ll
  llvm/test/CodeGen/X86/fp-intrinsics.ll
  llvm/test/CodeGen/X86/fp-strict-scalar-fptoint.ll
  llvm/test/CodeGen/X86/fp80-strict-scalar.ll
  llvm/test/CodeGen/X86/jump_sign.ll
  llvm/test/CodeGen/X86/midpoint-int.ll
  llvm/test/CodeGen/X86/pr22338.ll
  llvm/test/CodeGen/X86/pr33954.ll
  llvm/test/CodeGen/X86/pr47482.ll
  llvm/test/CodeGen/X86/scalar-fp-to-i64.ll
  llvm/test/CodeGen/X86/setcc-combine.ll
  llvm/test/CodeGen/X86/use-cr-result-of-dom-icmp-st.ll
  llvm/test/CodeGen/X86/vec-strict-fptoint-128.ll
  llvm/test/CodeGen/X86/vec-strict-fptoint-256.ll
  llvm/test/CodeGen/X86/vec-strict-fptoint-512.ll
  llvm/test/CodeGen/X86/zext-sext.ll
  llvm/test/tools/llvm-locstats/locstats.ll