[llvm] d5e4f28 - [SystemZ] Return true from isMaskAndCmp0FoldingBeneficial().

[Jonas Paulsson via llvm-commits]

Author: Jonas Paulsson
Date: 2021-06-08T15:42:46-05:00
New Revision: d5e4f28c0a45a659d45ae8a822c24d68fbadcfbd

URL: https://github.com/llvm/llvm-project/commit/d5e4f28c0a45a659d45ae8a822c24d68fbadcfbd
DIFF: https://github.com/llvm/llvm-project/commit/d5e4f28c0a45a659d45ae8a822c24d68fbadcfbd.diff

LOG: [SystemZ] Return true from isMaskAndCmp0FoldingBeneficial().

Return true if the mask is a constant uint of 2 bytes, in which case TMLL is
available.

Review: Ulrich Weigand

Added: 
    llvm/test/CodeGen/SystemZ/codegenprepare-sink-and-for-tm.ll

Modified: 
    llvm/lib/Target/SystemZ/SystemZISelLowering.h

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index d49e48f676aba..60969ffca59a5 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -437,6 +437,10 @@ class SystemZTargetLowering : public TargetLowering {
     EVT ScVT = VT.getScalarType();
     return ScVT == MVT::f32 || ScVT == MVT::f64 || ScVT == MVT::f128;
   }
+  bool isMaskAndCmp0FoldingBeneficial(const Instruction &AndI) const override {
+    ConstantInt* Mask = dyn_cast<ConstantInt>(AndI.getOperand(1));
+    return Mask && Mask->getValue().isIntN(16);
+  }
   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &,
                          EVT) const override;
   bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,

diff  --git a/llvm/test/CodeGen/SystemZ/codegenprepare-sink-and-for-tm.ll b/llvm/test/CodeGen/SystemZ/codegenprepare-sink-and-for-tm.ll
new file mode 100644
index 0000000000000..8c5128aee9f6c
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/codegenprepare-sink-and-for-tm.ll
@@ -0,0 +1,42 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z14 | FileCheck %s
+;
+; CGP will duplicate and sink the 'icmp' to the users. Test that it does the
+; same for the 'and' so that tmll:s result and the nilf is eliminated.
+
+define void @fun(i32 %Arg) {
+; CHECK-LABEL: fun:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    ahi %r2, 1
+; CHECK-NEXT:    lhi %r0, 0
+; CHECK-NEXT:    cijlh %r0, 0, .LBB0_2
+; CHECK-NEXT:  # %bb.1: # %bb1
+; CHECK-NEXT:    tmll %r2, 16
+; CHECK-NEXT:    lochie %r0, 1
+; CHECK-NEXT:    st %r0, 0(%r1)
+; CHECK-NEXT:    br %r14
+; CHECK-NEXT:  .LBB0_2: # %bb2
+; CHECK-NEXT:    tmll %r2, 16
+; CHECK-NEXT:    lhi %r0, 16
+; CHECK-NEXT:    lochie %r0, 4
+; CHECK-NEXT:    st %r0, 0(%r1)
+; CHECK-NEXT:    br %r14
+entry:
+  %A = add i32 %Arg, 1
+  %N = and i32 %A, 16
+  %i4 = icmp eq i32 %N, 0
+  br i1 undef, label %bb1, label %bb2
+
+bb1:
+  %i9 = zext i1 %i4 to i32
+  store i32 %i9, i32* undef
+  br label %bb3
+
+bb2:
+  %i13 = select i1 %i4, i32 4, i32 16
+  store i32 %i13, i32* undef
+  br label %bb3
+
+bb3:
+  ret void
+}