[SCCP] add tests for ashr range transforms; NFC

Author: rotateright

llvm/test/Transforms/SCCP/ashr.ll

@@ -0,0 +1,108 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=ipsccp -S < %s | FileCheck %s
+
+define i8 @ashr_and(i8 %x) {
+; CHECK-LABEL: @ashr_and(
+; CHECK-NEXT:    [[PX:%.*]] = and i8 [[X:%.*]], 127
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 [[PX]], 1
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %px = and i8 %x, 127
+  %r = ashr i8 %px, 1
+  ret i8 %r
+}
+
+define i8 @ashr_const(i8 %x) {
+; CHECK-LABEL: @ashr_const(
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 42, [[X:%.*]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %r = ashr i8 42, %x
+  ret i8 %r
+}
+
+define i8 @ashr_zext(i7 %x, i8 %y) {
+; CHECK-LABEL: @ashr_zext(
+; CHECK-NEXT:    [[PX:%.*]] = zext i7 [[X:%.*]] to i8
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 [[PX]], [[Y:%.*]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %px = zext i7 %x to i8
+  %r = ashr i8 %px, %y
+  ret i8 %r
+}
+
+define i8 @ashr_not_nonneg(i7 %x, i8 %y) {
+; CHECK-LABEL: @ashr_not_nonneg(
+; CHECK-NEXT:    [[PX:%.*]] = sext i7 [[X:%.*]] to i8
+; CHECK-NEXT:    [[R:%.*]] = ashr i8 [[PX]], [[Y:%.*]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %px = sext i7 %x to i8
+  %r = ashr i8 %px, %y
+  ret i8 %r
+}
+
+; x is known non-negative in t block
+
+define i32 @dominating_condition(i32 %x) {
+; CHECK-LABEL: @dominating_condition(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[X:%.*]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       t:
+; CHECK-NEXT:    [[A:%.*]] = ashr i32 [[X]], 16
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       f:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[COND:%.*]] = phi i32 [ [[A]], [[T]] ], [ 42, [[F]] ]
+; CHECK-NEXT:    ret i32 [[COND]]
+;
+entry:
+  %cmp = icmp sge i32 %x, 0
+  br i1 %cmp, label %t, label %f
+
+t:
+  %a = ashr i32 %x, 16
+  br label %exit
+
+f:
+  br label %exit
+
+exit:
+  %cond = phi i32 [ %a, %t ], [ 42, %f ]
+  ret i32 %cond
+}
+
+; x is known non-negative in f block
+
+define i32 @dominating_condition_alt(i32 %x, i32 %y) {
+; CHECK-LABEL: @dominating_condition_alt(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32 [[X:%.*]], 2000000000
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       t:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       f:
+; CHECK-NEXT:    [[A:%.*]] = ashr i32 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[COND:%.*]] = phi i32 [ -42, [[T]] ], [ [[A]], [[F]] ]
+; CHECK-NEXT:    ret i32 [[COND]]
+;
+entry:
+  %cmp = icmp ugt i32 %x, 2000000000
+  br i1 %cmp, label %t, label %f
+
+t:
+  br label %exit
+
+f:
+  %a = ashr i32 %x, %y
+  br label %exit
+
+exit:
+  %cond = phi i32 [ -42, %t ], [ %a, %f ]
+  ret i32 %cond
+}