[AArch64] Add tests showing unnecessary cast promotion.

Author: fhahn

llvm/test/CodeGen/AArch64/avoid-free-ext-promotion.ll

@@ -0,0 +1,146 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc -mtriple=arm64-apple-macosx -o - %s | FileCheck %s
+
+%struct.zot = type { ptr, i32, ptr, ptr, i32, i32, i32, i32, i32, i32 }
+
+; FIXME: currently the AND is performed on 64 bit unnecessarily.
+
+; Test cases where an AND is extended from i32 -> i64 which is free. Make
+; sure the extends do not get moved to the arguments, which would perform the
+; AND on 64 bits unnecessarily.
+
+define void @avoid_promotion_1_and(ptr nocapture noundef %arg, ptr %p) {
+; CHECK-LABEL: avoid_promotion_1_and:
+; CHECK:       ; %bb.0: ; %bb
+; CHECK-NEXT:    ldr w8, [x0, #52]
+; CHECK-NEXT:    mov w9, #10 ; =0xa
+; CHECK-NEXT:  LBB0_1: ; %bb8
+; CHECK-NEXT:    ; =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    cmp w8, #3
+; CHECK-NEXT:    b.lo LBB0_1
+; CHECK-NEXT:  ; %bb.2: ; %bb9
+; CHECK-NEXT:    ; in Loop: Header=BB0_1 Depth=1
+; CHECK-NEXT:    ldr w10, [x0, #32]
+; CHECK-NEXT:    ldr w11, [x1, #76]
+; CHECK-NEXT:    ldr w12, [x1]
+; CHECK-NEXT:    eor w10, w10, w11
+; CHECK-NEXT:    and x10, x10, x12
+; CHECK-NEXT:    str w10, [x0, #32]
+; CHECK-NEXT:    strh w9, [x1, x10, lsl #1]
+; CHECK-NEXT:    b LBB0_1
+bb:
+  %gep = getelementptr inbounds %struct.zot, ptr %arg, i64 0, i32 9
+  %l = load i32, ptr %gep, align 4
+  %icmp = icmp ugt i32 %l, 2
+  %gep1 = getelementptr inbounds %struct.zot, ptr %arg, i64 0, i32 4
+  %gep2 = getelementptr inbounds %struct.zot, ptr %arg, i64 0, i32 7
+  br label %bb8
+
+bb8:                                              ; preds = %bb27, %bb
+  br i1 %icmp, label %bb9, label %bb27
+
+bb9:                                              ; preds = %bb8
+  %l10 = load i32, ptr %gep1, align 8
+  %gep14 = getelementptr inbounds i32, ptr %p, i64 19
+  %l15 = load i32, ptr %gep14, align 1
+  %xor = xor i32 %l10, %l15
+  %l17 = load i32, ptr %p, align 8
+  %and = and i32 %xor, %l17
+  store i32 %and, ptr %gep1, align 8
+  %zext19 = zext i32 %and to i64
+  %gep20 = getelementptr inbounds i16, ptr %p, i64 %zext19
+  store i16 10, ptr %gep20, align 2
+  br label %bb27
+
+bb27:                                             ; preds = %bb9, %bb8
+  br label %bb8
+}
+
+define void @avoid_promotion_2_and(ptr nocapture noundef %arg) {
+; CHECK-LABEL: avoid_promotion_2_and:
+; CHECK:       ; %bb.0: ; %entry
+; CHECK-NEXT:    add x8, x0, #32
+; CHECK-NEXT:    b LBB1_2
+; CHECK-NEXT:  LBB1_1: ; %latch
+; CHECK-NEXT:    ; in Loop: Header=BB1_2 Depth=1
+; CHECK-NEXT:    cmp w9, #2
+; CHECK-NEXT:    add x8, x8, #56
+; CHECK-NEXT:    b.ls LBB1_4
+; CHECK-NEXT:  LBB1_2: ; %loop
+; CHECK-NEXT:    ; =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    ldr w9, [x8, #20]
+; CHECK-NEXT:    cmp w9, #3
+; CHECK-NEXT:    b.lo LBB1_1
+; CHECK-NEXT:  ; %bb.3: ; %then
+; CHECK-NEXT:    ; in Loop: Header=BB1_2 Depth=1
+; CHECK-NEXT:    ldp w13, w12, [x8, #12]
+; CHECK-NEXT:    ldr w10, [x8]
+; CHECK-NEXT:    ldr x11, [x0]
+; CHECK-NEXT:    ldr w14, [x8, #8]
+; CHECK-NEXT:    lsl w10, w10, w13
+; CHECK-NEXT:    ldrb w11, [x11, x12]
+; CHECK-NEXT:    eor w10, w10, w11
+; CHECK-NEXT:    ldur w11, [x8, #-24]
+; CHECK-NEXT:    and x10, x10, x14
+; CHECK-NEXT:    ldp x15, x14, [x8, #-16]
+; CHECK-NEXT:    lsl x13, x10, #1
+; CHECK-NEXT:    str w10, [x8]
+; CHECK-NEXT:    and x10, x11, x12
+; CHECK-NEXT:    ldrh w11, [x14, x13]
+; CHECK-NEXT:    strh w11, [x15, x10, lsl #1]
+; CHECK-NEXT:    strh w12, [x14, x13]
+; CHECK-NEXT:    b LBB1_1
+; CHECK-NEXT:  LBB1_4: ; %exit
+; CHECK-NEXT:    ret
+entry:
+  br label %loop
+
+loop:
+  %p = phi i64 [ 0, %entry ], [ %p.next, %latch ]
+  %gep = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 9
+  %l = load i32, ptr %gep, align 4
+  %icmp = icmp ugt i32 %l, 2
+  %gep1 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 4
+  %gep2 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 7
+  %gep3 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 8
+  %gep4 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 6
+  %gep5 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 3
+  %gep6 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 2
+  %gep7 = getelementptr inbounds %struct.zot, ptr %arg, i64 %p, i32 1
+  br i1 %icmp, label %then, label %latch
+
+then:
+  %l10 = load i32, ptr %gep1, align 8
+  %l11 = load i32, ptr %gep2, align 4
+  %shl = shl i32 %l10, %l11
+  %l12 = load ptr, ptr %arg, align 8
+  %l13 = load i32, ptr %gep3, align 8
+  %zext = zext i32 %l13 to i64
+  %gep14 = getelementptr inbounds i8, ptr %l12, i64 %zext
+  %l15 = load i8, ptr %gep14, align 1
+  %zext16 = zext i8 %l15 to i32
+  %xor = xor i32 %shl, %zext16
+  %l17 = load i32, ptr %gep4, align 8
+  %and = and i32 %xor, %l17
+  store i32 %and, ptr %gep1, align 8
+  %l18 = load ptr, ptr %gep5, align 8
+  %zext19 = zext i32 %and to i64
+  %gep20 = getelementptr inbounds i16, ptr %l18, i64 %zext19
+  %l21 = load i16, ptr %gep20, align 2
+  %l22 = load ptr, ptr %gep6, align 8
+  %l23 = load i32, ptr %gep7, align 8
+  %and24 = and i32 %l23, %l13
+  %zext25 = zext i32 %and24 to i64
+  %gep26 = getelementptr inbounds i16, ptr %l22, i64 %zext25
+  store i16 %l21, ptr %gep26, align 2
+  %trunc = trunc i32 %l13 to i16
+  store i16 %trunc, ptr %gep20, align 2
+  br label %latch
+
+latch:
+  %p.next = add i64 %p, 1
+  br i1 %icmp, label %loop, label %exit
+
+exit:
+  ret void
+}