(apply [{ return Helper.replaceSingleDefInstWithOperand(*${root}, 1); }])
>;
+// Fold (x op x) - > x
+def binop_same_val: GICombineRule<
+ (defs root:$root),
+ (match (wip_match_opcode G_AND, G_OR):$root,
+ [{ return Helper.matchBinOpSameVal(*${root}); }]),
+ (apply [{ return Helper.replaceSingleDefInstWithOperand(*${root}, 1); }])
+>;
+
// FIXME: These should use the custom predicate feature once it lands.
def undef_combines : GICombineGroup<[undef_to_fp_zero, undef_to_int_zero,
undef_to_negative_one,
propagate_undef_all_ops,
propagate_undef_shuffle_mask]>;
-def identity_combines : GICombineGroup<[select_same_val, right_identity_zero]>;
+def identity_combines : GICombineGroup<[select_same_val, right_identity_zero,
+ binop_same_val]>;
def trivial_combines : GICombineGroup<[copy_prop, mul_to_shl]>;
def all_combines : GICombineGroup<[trivial_combines, ptr_add_immed_chain,
--- /dev/null
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple aarch64 -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+
+name: or_same
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $x0
+
+ ; Fold: x or x -> x
+ ; CHECK-LABEL: name: or_same
+ ; CHECK: liveins: $x0
+ ; CHECK: %copy:_(s64) = COPY $x0
+ ; CHECK: $x0 = COPY %copy(s64)
+ ; CHECK: RET_ReallyLR implicit $x0
+ %copy:_(s64) = COPY $x0
+ %or:_(s64) = G_OR %copy, %copy
+ $x0 = COPY %or(s64)
+ RET_ReallyLR implicit $x0
+
+...
+---
+name: and_same
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $x0
+
+ ; Fold: x and x -> x
+
+ ; CHECK-LABEL: name: and_same
+ ; CHECK: liveins: $x0
+ ; CHECK: %copy:_(s64) = COPY $x0
+ ; CHECK: $x0 = COPY %copy(s64)
+ ; CHECK: RET_ReallyLR implicit $x0
+ %copy:_(s64) = COPY $x0
+ %and:_(s64) = G_AND %copy, %copy
+ $x0 = COPY %and(s64)
+ RET_ReallyLR implicit $x0
+
+...
+---
+name: and_same2
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $x0, $x1
+
+ ; We can fold when the LHS and RHS are guaranteed to be identical.
+
+ ; CHECK-LABEL: name: and_same2
+ ; CHECK: liveins: $x0, $x1
+ ; CHECK: %copy1:_(s64) = COPY $x0
+ ; CHECK: %copy2:_(s64) = COPY $x1
+ ; CHECK: %or:_(s64) = G_OR %copy1, %copy2
+ ; CHECK: $x0 = COPY %or(s64)
+ ; CHECK: RET_ReallyLR implicit $x0
+ %copy1:_(s64) = COPY $x0
+ %copy2:_(s64) = COPY $x1
+ %or:_(s64) = G_OR %copy1, %copy2
+ %same_as_or:_(s64) = COPY %or(s64)
+ %and:_(s64) = G_AND %or, %same_as_or
+ $x0 = COPY %and(s64)
+ RET_ReallyLR implicit $x0
+
+...
+---
+name: or_and_not_same
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $x0, $x1, $x2
+
+ ; None of the G_ORs or G_ANDs should be eliminated here, because their LHS
+ ; and RHS values are different.
+
+ ; CHECK-LABEL: name: or_and_not_same
+ ; CHECK: liveins: $x0, $x1, $x2
+ ; CHECK: %copy1:_(s64) = COPY $x0
+ ; CHECK: %copy2:_(s64) = COPY $x1
+ ; CHECK: %copy3:_(s64) = COPY $x2
+ ; CHECK: %or1:_(s64) = G_OR %copy1, %copy2
+ ; CHECK: %or2:_(s64) = G_OR %copy1, %copy3
+ ; CHECK: %and:_(s64) = G_AND %or1, %or2
+ ; CHECK: $x0 = COPY %and(s64)
+ ; CHECK: RET_ReallyLR implicit $x0
+ %copy1:_(s64) = COPY $x0
+ %copy2:_(s64) = COPY $x1
+ %copy3:_(s64) = COPY $x2
+ %or1:_(s64) = G_OR %copy1, %copy2
+ %or2:_(s64) = G_OR %copy1, %copy3
+ %and:_(s64) = G_AND %or1, %or2
+ $x0 = COPY %and(s64)
+ RET_ReallyLR implicit $x0
+
+...