[CSKY] Optimize ANDI/ORI to BSETI/BCLRI for specific immediates

Reviewed By: zixuan-wu Differential Revision: https://reviews.llvm.org/D153614
llvm · Aug 4, 2023 · 528831d · 528831d
1 parent f3b9b94
commit 528831d
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Showing 2 changed files with 34 additions and 5 deletions.
diff --git a/llvm/lib/Target/CSKY/CSKYInstrInfo.td b/llvm/lib/Target/CSKY/CSKYInstrInfo.td
@@ -158,6 +158,30 @@ def uimm_shift : Operand<i32>, ImmLeaf<i32, "return isUInt<2>(Imm);"> {
   let DecoderMethod = "decodeImmShiftOpValue";
 }
 
+// Optimize (or x, imm) to (BSETI x, log2(imm)). We should exclude the
+// case can be opimized to (ORI32/ORI16 x, imm).
+def imm32_1_pop_bit_XFORM : SDNodeXForm<imm, [{
+  uint32_t I = N->getZExtValue();
+  return CurDAG->getTargetConstant(llvm::Log2_32(I), SDLoc(N),
+                                   N->getValueType(0));
+}]>;
+def imm32_1_pop_bit : PatLeaf<(imm), [{
+  uint32_t I = N->getZExtValue();
+  return llvm::popcount(I) == 1 && I > 0xffff;
+}]>;
+
+// Optimize (and x, imm) to (BCLRI x, log2(~imm)). We should exclude the
+// case can be opimized to (ANDNI x, ~imm).
+def imm32_1_zero_bit_XFORM : SDNodeXForm<imm, [{
+  uint32_t I = ~N->getZExtValue();
+  return CurDAG->getTargetConstant(llvm::Log2_32(I), SDLoc(N),
+                                   N->getValueType(0));
+}]>;
+def imm32_1_zero_bit : PatLeaf<(imm), [{
+  uint32_t I = ~N->getZExtValue();
+  return llvm::popcount(I) == 1 && I > 0xfff;
+}]>;
+
 def CSKYSymbol : AsmOperandClass {
   let Name = "CSKYSymbol";
   let RenderMethod = "addImmOperands";
@@ -1422,6 +1446,14 @@ let Predicates = [iHasE2] in
   def : Pat<(i32 imm:$imm),
             (ORI32 (MOVIH32 (uimm32_hi16 imm:$imm)), (uimm32_lo16 imm:$imm))>;
 
+// Bit operations.
+let Predicates = [iHasE2] in {
+  def : Pat<(or GPR:$rs, imm32_1_pop_bit:$imm),
+            (BSETI32 GPR:$rs, (imm32_1_pop_bit_XFORM imm32_1_pop_bit:$imm))>;
+  def : Pat<(and GPR:$rs, imm32_1_zero_bit:$imm),
+            (BCLRI32 GPR:$rs, (imm32_1_zero_bit_XFORM imm32_1_zero_bit:$imm))>;
+}
+
 // Other operations.
 let Predicates = [iHasE2] in {
   def : Pat<(rotl GPR:$rs1, GPR:$rs2),

diff --git a/llvm/test/CodeGen/CSKY/bseti_bclri.ll b/llvm/test/CodeGen/CSKY/bseti_bclri.ll
@@ -13,8 +13,7 @@ define i32 @test_or_128(i32 noundef %0) {
 define i32 @test_or_131072(i32 noundef %0) {
 ; CHECK-LABEL: test_or_131072:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movih32 a1, 2
-; CHECK-NEXT:    or16 a0, a1
+; CHECK-NEXT:    bseti16 a0, 17
 ; CHECK-NEXT:    rts16
  %2 = or i32 %0, 131072
  ret i32 %2
@@ -71,9 +70,7 @@ define i32 @test_andnot_128(i32 noundef %0) {
 define i32 @test_andnot_131072(i32 noundef %0) {
 ; CHECK-LABEL: test_andnot_131072:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movih32 a1, 65533
-; CHECK-NEXT:    ori32 a1, a1, 65535
-; CHECK-NEXT:    and16 a0, a1
+; CHECK-NEXT:    bclri16 a0, 17
 ; CHECK-NEXT:    rts16
  %2 = and i32 %0, -131073
  ret i32 %2