[InstCombine] Tests for adding flags to shifts; NFC

[goldstein.w.n]

moving to gh.

llvm/test/Transforms/InstCombine/shift-flags.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i8 @shl_add_nuw(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @shl_add_nuw(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], 63
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = shl i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, 63
+  %cnt = and i8 %cnt_in, 2
+  %r = shl i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @shl_add_nuw_fail(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @shl_add_nuw_fail(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], 63
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 3
+; CHECK-NEXT:    [[R:%.*]] = shl i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, 63
+  %cnt = and i8 %cnt_in, 3
+  %r = shl i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @shl_add_nuw_and_nsw(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @shl_add_nuw_and_nsw(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], 31
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = shl i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, 31
+  %cnt = and i8 %cnt_in, 2
+  %r = shl i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @shl_add_nsw(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @shl_add_nsw(
+; CHECK-NEXT:    [[AMT:%.*]] = or i8 [[AMT_IN:%.*]], -32
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = shl i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = or i8 %amt_in, 224
+  %cnt = and i8 %cnt_in, 2
+  %r = shl i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @shl_add_nsw_fail(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @shl_add_nsw_fail(
+; CHECK-NEXT:    [[AMT:%.*]] = or i8 [[AMT_IN:%.*]], -64
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = shl i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = or i8 %amt_in, 192
+  %cnt = and i8 %cnt_in, 2
+  %r = shl i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @lshr_add_exact(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @lshr_add_exact(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], -4
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = lshr i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, -4
+  %cnt = and i8 %cnt_in, 2
+  %r = lshr i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @lshr_add_exact_fail(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @lshr_add_exact_fail(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], -7
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = lshr i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, -7
+  %cnt = and i8 %cnt_in, 2
+  %r = lshr i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @ashr_add_exact(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @ashr_add_exact(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], -14
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 1
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, -14
+  %cnt = and i8 %cnt_in, 1
+  %r = ashr i8 %amt, %cnt
+  ret i8 %r
+}
+
+define i8 @ashr_add_exact_fail(i8 %amt_in, i8 %cnt_in) {
+; CHECK-LABEL: @ashr_add_exact_fail(
+; CHECK-NEXT:    [[AMT:%.*]] = and i8 [[AMT_IN:%.*]], -14
+; CHECK-NEXT:    [[CNT:%.*]] = and i8 [[CNT_IN:%.*]], 2
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 [[AMT]], [[CNT]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %amt = and i8 %amt_in, -14
+  %cnt = and i8 %cnt_in, 2
+  %r = ashr i8 %amt, %cnt
+  ret i8 %r
+}