[GISel][CombinerHelper] Combine op(trunc(x), trunc(y)) -> trunc(op(x,…

… y)) (#89023)

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

@@ -3158,6 +3158,22 @@ bool CombinerHelper::matchHoistLogicOpWithSameOpcodeHands(
     // Match: logic (ext X), (ext Y) --> ext (logic X, Y)
     break;
   }
+  case TargetOpcode::G_TRUNC: {
+    // Match: logic (trunc X), (trunc Y) -> trunc (logic X, Y)
+    const MachineFunction *MF = MI.getMF();
+    const DataLayout &DL = MF->getDataLayout();
+    LLVMContext &Ctx = MF->getFunction().getContext();
+
+    LLT DstTy = MRI.getType(Dst);
+    const TargetLowering &TLI = getTargetLowering();
+
+    // Be extra careful sinking truncate. If it's free, there's no benefit in
+    // widening a binop.
+    if (TLI.isZExtFree(DstTy, XTy, DL, Ctx) &&
+        TLI.isTruncateFree(XTy, DstTy, DL, Ctx))
+      return false;
+    break;
+  }
   case TargetOpcode::G_AND:
   case TargetOpcode::G_ASHR:
   case TargetOpcode::G_LSHR:

llvm/test/CodeGen/AArch64/GlobalISel/combine-op-trunc.mir

@@ -0,0 +1,315 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -o - -mtriple=aarch64-unknown-unknown -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs  %s | FileCheck %s
+
+# Truncs with a single use get folded.
+
+# and(trunc(x), trunc(y)) -> trunc(and(x, y))
+---
+name:            and_trunc
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: and_trunc
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $w0 = COPY [[AND]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %4:_(s16) = G_AND %2, %3
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+---
+name:            and_trunc_vector
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: and_trunc_vector
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $q0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $q1
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(<4 x s32>) = G_AND [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(<4 x s16>) = G_TRUNC [[AND]](<4 x s32>)
+    ; CHECK-NEXT: $x0 = COPY [[TRUNC]](<4 x s16>)
+    %0:_(<4 x s32>) = COPY $q0
+    %1:_(<4 x s32>) = COPY $q1
+    %2:_(<4 x s16>) = G_TRUNC %0
+    %3:_(<4 x s16>) = G_TRUNC %1
+    %4:_(<4 x s16>) = G_AND %2, %3
+    $x0 = COPY %4
+...
+
+# or(trunc(x), trunc(y)) -> trunc(or(x, y))
+---
+name:            or_trunc
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: or_trunc
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s32) = G_OR [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $w0 = COPY [[OR]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %4:_(s16) = G_OR %2, %3
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+---
+name:            or_trunc_vector
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: or_trunc_vector
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $q0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $q1
+    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(<4 x s32>) = G_OR [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(<4 x s16>) = G_TRUNC [[OR]](<4 x s32>)
+    ; CHECK-NEXT: $x0 = COPY [[TRUNC]](<4 x s16>)
+    %0:_(<4 x s32>) = COPY $q0
+    %1:_(<4 x s32>) = COPY $q1
+    %2:_(<4 x s16>) = G_TRUNC %0
+    %3:_(<4 x s16>) = G_TRUNC %1
+    %4:_(<4 x s16>) = G_OR %2, %3
+    $x0 = COPY %4
+...
+
+# xor(trunc(x), trunc(y)) -> trunc(xor(x, y))
+---
+name:            xor_trunc
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: xor_trunc
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $w0 = COPY [[XOR]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %4:_(s16) = G_XOR %2, %3
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+---
+name:            xor_trunc_vector
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: xor_trunc_vector
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $q0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $q1
+    ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(<4 x s32>) = G_XOR [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(<4 x s16>) = G_TRUNC [[XOR]](<4 x s32>)
+    ; CHECK-NEXT: $x0 = COPY [[TRUNC]](<4 x s16>)
+    %0:_(<4 x s32>) = COPY $q0
+    %1:_(<4 x s32>) = COPY $q1
+    %2:_(<4 x s16>) = G_TRUNC %0
+    %3:_(<4 x s16>) = G_TRUNC %1
+    %4:_(<4 x s16>) = G_XOR %2, %3
+    $x0 = COPY %4
+...
+
+# Truncs with multiple uses do not get folded.
+---
+name:            or_trunc_multiuse_1
+body:             |
+  bb.0:
+    liveins: $w0, $w1, $x2
+    ; CHECK-LABEL: name: or_trunc_multiuse_1
+    ; CHECK: liveins: $w0, $w1, $x2
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(p0) = COPY $x2
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK-NEXT: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[COPY1]](s32)
+    ; CHECK-NEXT: G_STORE [[TRUNC]](s16), [[COPY2]](p0) :: (store (s16))
+    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s16) = G_OR [[TRUNC]], [[TRUNC1]]
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[OR]](s16)
+    ; CHECK-NEXT: $w0 = COPY [[ANYEXT]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %5:_(p0) = COPY $x2
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    G_STORE %2, %5 :: (store (s16))
+    %4:_(s16) = G_OR %2, %3
+    %6:_(s32) = G_ANYEXT %4
+    $w0 = COPY %6
+...
+---
+name:            and_trunc_multiuse_2
+body:             |
+  bb.0:
+    liveins: $w0, $w1, $x2
+    ; CHECK-LABEL: name: and_trunc_multiuse_2
+    ; CHECK: liveins: $w0, $w1, $x2
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(p0) = COPY $x2
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK-NEXT: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[COPY1]](s32)
+    ; CHECK-NEXT: G_STORE [[TRUNC]](s16), [[COPY2]](p0) :: (store (s16))
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s16) = G_AND [[TRUNC]], [[TRUNC1]]
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[AND]](s16)
+    ; CHECK-NEXT: $w0 = COPY [[ANYEXT]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %5:_(p0) = COPY $x2
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    G_STORE %2, %5 :: (store (s16))
+    %4:_(s16) = G_AND %2, %3
+    %6:_(s32) = G_ANYEXT %4
+    $w0 = COPY %6
+...
+---
+name:            xor_trunc_vector_multiuse
+body:             |
+  bb.0:
+    liveins: $w0, $w1, $x2
+    ; CHECK-LABEL: name: xor_trunc_vector_multiuse
+    ; CHECK: liveins: $w0, $w1, $x2
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $q0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $q1
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(p0) = COPY $x2
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(<4 x s16>) = G_TRUNC [[COPY]](<4 x s32>)
+    ; CHECK-NEXT: [[TRUNC1:%[0-9]+]]:_(<4 x s16>) = G_TRUNC [[COPY1]](<4 x s32>)
+    ; CHECK-NEXT: G_STORE [[TRUNC]](<4 x s16>), [[COPY2]](p0) :: (store (<4 x s16>))
+    ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(<4 x s16>) = G_XOR [[TRUNC]], [[TRUNC1]]
+    ; CHECK-NEXT: $x0 = COPY [[XOR]](<4 x s16>)
+    %0:_(<4 x s32>) = COPY $q0
+    %1:_(<4 x s32>) = COPY $q1
+    %5:_(p0) = COPY $x2
+    %2:_(<4 x s16>) = G_TRUNC %0
+    %3:_(<4 x s16>) = G_TRUNC %1
+    G_STORE %2, %5 :: (store (<4 x s16>))
+    %4:_(<4 x s16>) = G_XOR %2, %3
+    $x0 = COPY %4
+...
+
+# Freezes should get pushed through truncs.
+
+# This optimizes the pattern where `select(cond, T, 0)` gets converted to
+# `and(cond, freeze(T))`.
+
+# and(freeze(trunc(x)), trunc(y)) -> trunc(and(freeze(x), y))
+---
+name:            and_trunc_freeze
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: and_trunc_freeze
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s32) = G_FREEZE [[COPY]]
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[FREEZE]], [[COPY1]]
+    ; CHECK-NEXT: $w0 = COPY [[AND]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %6:_(s16) = G_FREEZE %2
+    %4:_(s16) = G_AND %6, %3
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+
+# and(freeze(trunc(x)), freeze(trunc(y))) -> trunc(and(freeze(x), freeze(y)))
+---
+name:            and_trunc_freeze_both
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: and_trunc_freeze_both
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s32) = G_FREEZE [[COPY]]
+    ; CHECK-NEXT: [[FREEZE1:%[0-9]+]]:_(s32) = G_FREEZE [[COPY1]]
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[FREEZE]], [[FREEZE1]]
+    ; CHECK-NEXT: $w0 = COPY [[AND]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %6:_(s16) = G_FREEZE %2
+    %7:_(s16) = G_FREEZE %3
+    %4:_(s16) = G_AND %6, %7
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+
+# The freeze fold is less important for G_OR and G_XOR, however it can still
+# trigger.
+---
+name:            or_trunc_freeze
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: or_trunc_freeze
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s32) = G_FREEZE [[COPY]]
+    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s32) = G_OR [[FREEZE]], [[COPY1]]
+    ; CHECK-NEXT: $w0 = COPY [[OR]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %6:_(s16) = G_FREEZE %2
+    %4:_(s16) = G_OR %6, %3
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...
+---
+name:            xor_trunc_freeze_both
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+    ; CHECK-LABEL: name: xor_trunc_freeze_both
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s32) = G_FREEZE [[COPY]]
+    ; CHECK-NEXT: [[FREEZE1:%[0-9]+]]:_(s32) = G_FREEZE [[COPY1]]
+    ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[FREEZE]], [[FREEZE1]]
+    ; CHECK-NEXT: $w0 = COPY [[XOR]](s32)
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s16) = G_TRUNC %0
+    %3:_(s16) = G_TRUNC %1
+    %6:_(s16) = G_FREEZE %2
+    %7:_(s16) = G_FREEZE %3
+    %4:_(s16) = G_XOR %6, %7
+    %5:_(s32) = G_ANYEXT %4
+    $w0 = COPY %5
+...