1 files changed, 262 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/narrow-switch.ll b/llvm/test/Transforms/InstCombine/narrow-switch.ll
new file mode 100644
index 00000000000..a8fa3e528db
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/narrow-switch.ll
@@ -0,0 +1,262 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; Vary legal integer types in data layout.
+; RUN: opt < %s -instcombine -S -data-layout=n32    | FileCheck %s --check-prefix=ALL --check-prefix=CHECK32
+; RUN: opt < %s -instcombine -S -data-layout=n32:64 | FileCheck %s --check-prefix=ALL --check-prefix=CHECK64
+
+define i32 @positive1(i64 %a) {
+; ALL-LABEL: @positive1(
+; ALL:         switch i32
+; ALL-NEXT:    i32 10, label %return
+; ALL-NEXT:    i32 100, label %sw.bb1
+; ALL-NEXT:    i32 1001, label %sw.bb2
+; ALL-NEXT:    ]
+;
+entry:
+  %and = and i64 %a, 4294967295
+  switch i64 %and, label %sw.default [
+  i64 10, label %return
+  i64 100, label %sw.bb1
+  i64 1001, label %sw.bb2
+  ]
+
+sw.bb1:
+  br label %return
+
+sw.bb2:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval.0 = phi i32 [ 24, %sw.default ], [ 123, %sw.bb2 ], [ 213, %sw.bb1 ], [ 231, %entry ]
+  ret i32 %retval.0
+}
+
+define i32 @negative1(i64 %a) {
+; ALL-LABEL: @negative1(
+; ALL:         switch i32
+; ALL-NEXT:    i32 -10, label %return
+; ALL-NEXT:    i32 -100, label %sw.bb1
+; ALL-NEXT:    i32 -1001, label %sw.bb2
+; ALL-NEXT:    ]
+;
+entry:
+  %or = or i64 %a, -4294967296
+  switch i64 %or, label %sw.default [
+  i64 -10, label %return
+  i64 -100, label %sw.bb1
+  i64 -1001, label %sw.bb2
+  ]
+
+sw.bb1:
+  br label %return
+
+sw.bb2:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval.0 = phi i32 [ 24, %sw.default ], [ 123, %sw.bb2 ], [ 213, %sw.bb1 ], [ 231, %entry ]
+  ret i32 %retval.0
+}
+
+; Make sure truncating a constant int larger than 64-bit doesn't trigger an
+; assertion.
+
+define i32 @trunc72to68(i72 %a) {
+; ALL-LABEL: @trunc72to68(
+; ALL:         switch i68
+; ALL-NEXT:    i68 10, label %return
+; ALL-NEXT:    i68 100, label %sw.bb1
+; ALL-NEXT:    i68 1001, label %sw.bb2
+; ALL-NEXT:    ]
+;
+entry:
+  %and = and i72 %a, 295147905179352825855
+  switch i72 %and, label %sw.default [
+  i72 10, label %return
+  i72 100, label %sw.bb1
+  i72 1001, label %sw.bb2
+  ]
+
+sw.bb1:
+  br label %return
+
+sw.bb2:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval.0 = phi i32 [ 24, %sw.default ], [ 123, %sw.bb2 ], [ 213, %sw.bb1 ], [ 231, %entry ]
+  ret i32 %retval.0
+}
+
+; Make sure to avoid assertion crashes and use the type before
+; truncation to generate the sub constant expressions that leads
+; to the recomputed condition.
+; We allow to truncate from i64 to i59 if in 32-bit mode,
+; because both are illegal.
+
+define void @trunc64to59(i64 %a) {
+; ALL-LABEL: @trunc64to59(
+; ALL-CHECK32:         switch i59
+; ALL-CHECK32-NEXT:    i59 0, label %sw.bb1
+; ALL-CHECK32-NEXT:    i59 18717182647723699, label %sw.bb2
+; ALL-CHECK32-NEXT:    ]
+; ALL-CHECK64:         switch i64
+; ALL-CHECK64-NEXT:    i64 0, label %sw.bb1
+; ALL-CHECK64-NEXT:    i64 18717182647723699, label %sw.bb2
+; ALL-CHECK64-NEXT:    ]
+;
+entry:
+  %tmp0 = and i64 %a, 15
+  %tmp1 = mul i64 %tmp0, -6425668444178048401
+  %tmp2 = add i64 %tmp1, 5170979678563097242
+  %tmp3 = mul i64 %tmp2, 1627972535142754813
+  switch i64 %tmp3, label %sw.default [
+  i64 847514119312061490, label %sw.bb1
+  i64 866231301959785189, label %sw.bb2
+  ]
+
+sw.bb1:
+  br label %sw.default
+
+sw.bb2:
+  br label %sw.default
+
+sw.default:
+  ret void
+}
+
+; https://llvm.org/bugs/show_bug.cgi?id=31260
+
+define i8 @PR31260(i8 %x) {
+; ALL-LABEL: @PR31260(
+; ALL-NEXT:  entry:
+; ALL-NEXT:    [[TMP0:%.*]] = trunc i8 %x to i2
+; ALL-NEXT:    [[TRUNC:%.*]] = and i2 [[TMP0]], -2
+; ALL-NEXT:    switch i2 [[TRUNC]], label %exit [
+; ALL-NEXT:    i2 0, label %case126
+; ALL-NEXT:    i2 -2, label %case124
+; ALL-NEXT:    ]
+; ALL:       exit:
+; ALL-NEXT:    ret i8 1
+; ALL:       case126:
+; ALL-NEXT:    ret i8 3
+; ALL:       case124:
+; ALL-NEXT:    ret i8 5
+;
+entry:
+  %t4 = and i8 %x, 2
+  %t5 = add nsw i8 %t4, -126
+  switch i8 %t5, label %exit [
+  i8 -126, label %case126
+  i8 -124, label %case124
+  ]
+
+exit:
+  ret i8 1
+case126:
+  ret i8 3
+case124:
+  ret i8 5
+}
+
+; Make sure the arithmetic evaluation of the switch
+; condition is evaluated on the original type
+define i32 @trunc32to16(i32 %a0) #0 {
+; ALL-LABEL: @trunc32to16(
+; ALL:         switch i16
+; ALL-NEXT:    i16 63, label %sw.bb
+; ALL-NEXT:    i16 1, label %sw.bb1
+; ALL-NEXT:    i16 100, label %sw.bb2
+; ALL-NEXT:    ]
+;
+entry:
+  %retval = alloca i32, align 4
+  %xor = xor i32 %a0, 1034460917
+  %shr = lshr i32 %xor, 16
+  %add = add i32 %shr, -917677090
+  switch i32 %add, label %sw.epilog [
+    i32 -917677027, label %sw.bb
+    i32 -917677089, label %sw.bb1
+    i32 -917676990, label %sw.bb2
+  ]
+
+sw.bb:                                            ; preds = %entry
+  store i32 90, i32* %retval, align 4
+  br label %return
+
+sw.bb1:                                           ; preds = %entry
+  store i32 91, i32* %retval, align 4
+  br label %return
+
+sw.bb2:                                           ; preds = %entry
+  store i32 92, i32* %retval, align 4
+  br label %return
+
+sw.epilog:                                        ; preds = %entry
+  store i32 113, i32* %retval, align 4
+  br label %return
+
+return:                                           ; preds = %sw.epilog, %sw.bb2,
+  %rval = load i32, i32* %retval, align 4
+  ret i32 %rval
+}
+
+; https://llvm.org/bugs/show_bug.cgi?id=29009
+
+@a = global i32 0, align 4
+@njob = global i32 0, align 4
+
+declare i32 @goo()
+
+; Make sure we do not shrink to illegal types (i3 in this case)
+; if original type is legal (i32 in this case)
+
+define void @PR29009() {
+; ALL-LABEL: @PR29009(
+; ALL:         switch i32
+; ALL-NEXT:    i32 0, label
+; ALL-NEXT:    i32 3, label
+; ALL-NEXT:    ]
+;
+  br label %1
+
+; <label>:1:                                      ; preds = %10, %0
+  %2 = load volatile i32, i32* @njob, align 4
+  %3 = icmp ne i32 %2, 0
+  br i1 %3, label %4, label %11
+
+; <label>:4:                                      ; preds = %1
+  %5 = call i32 @goo()
+  %6 = and i32 %5, 7
+  switch i32 %6, label %7 [
+    i32 0, label %8
+    i32 3, label %9
+  ]
+
+; <label>:7:                                      ; preds = %4
+  store i32 6, i32* @a, align 4
+  br label %10
+
+; <label>:8:                                      ; preds = %4
+  store i32 1, i32* @a, align 4
+  br label %10
+
+; <label>:9:                                      ; preds = %4
+  store i32 2, i32* @a, align 4
+  br label %10
+
+; <label>:10:                                     ; preds = %13, %12, %11, %10, %9, %8, %7
+  br label %1
+
+; <label>:11:                                     ; preds = %1
+  ret void
+}
+