[InstCombine] Add extra tests.

Author: fhahn

llvm/test/Transforms/InstCombine/sink-dereferenceable-assume.ll

@@ -1,11 +1,11 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
 ; RUN: opt -p instcombine -S %s | FileCheck %s
 
-define i64 @test_sink_with_dereferenceable_assume(ptr %p, ptr %q, i1 %cond) {
-; CHECK-LABEL: define i64 @test_sink_with_dereferenceable_assume(
-; CHECK-SAME: ptr [[P:%.*]], ptr [[Q:%.*]], i1 [[COND:%.*]]) {
+define i64 @test_dereferenceable_assume(ptr %p, ptr %q, i1 %c.0) {
+; CHECK-LABEL: define i64 @test_dereferenceable_assume(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[Q:%.*]], i1 [[C_0:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    br i1 [[COND]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK-NEXT:    br i1 [[C_0]], label %[[THEN:.*]], label %[[ELSE:.*]]
 ; CHECK:       [[THEN]]:
 ; CHECK-NEXT:    [[Q_INT:%.*]] = ptrtoint ptr [[Q]] to i64
 ; CHECK-NEXT:    [[P_INT:%.*]] = ptrtoint ptr [[P]] to i64
@@ -19,7 +19,7 @@ entry:
   %q_int = ptrtoint ptr %q to i64
   %diff = sub i64 %q_int, %p_int
   call void @llvm.assume(i1 true) [ "dereferenceable"(ptr %p, i64 %diff) ]
-  br i1 %cond, label %then, label %else
+  br i1 %c.0, label %then, label %else
 
 then:
   ret i64 %diff
@@ -28,4 +28,93 @@ else:
   ret i64 0
 }
 
+define i64 @test_sink_with_dereferenceable_assume_same_block_as_user(ptr %p, ptr %q, i1 %c.0) {
+; CHECK-LABEL: define i64 @test_sink_with_dereferenceable_assume_same_block_as_user(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[Q:%.*]], i1 [[C_0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    br i1 [[C_0]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    [[Q_INT:%.*]] = ptrtoint ptr [[Q]] to i64
+; CHECK-NEXT:    [[P_INT:%.*]] = ptrtoint ptr [[P]] to i64
+; CHECK-NEXT:    [[DIFF:%.*]] = sub i64 [[Q_INT]], [[P_INT]]
+; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "dereferenceable"(ptr [[P]], i64 [[DIFF]]) ]
+; CHECK-NEXT:    ret i64 [[DIFF]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    ret i64 0
+;
+entry:
+  %p_int = ptrtoint ptr %p to i64
+  %q_int = ptrtoint ptr %q to i64
+  %diff = sub i64 %q_int, %p_int
+  br i1 %c.0, label %then, label %else
+
+then:
+  call void @llvm.assume(i1 true) [ "dereferenceable"(ptr %p, i64 %diff) ]
+  ret i64 %diff
+
+else:
+  ret i64 0
+}
+
+define i64 @test_sink_with_multiple_users_dominated_by_deref(ptr %p, ptr %q, i1 %c.0, i1 %c.1) {
+; CHECK-LABEL: define i64 @test_sink_with_multiple_users_dominated_by_deref(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[Q:%.*]], i1 [[C_0:%.*]], i1 [[C_1:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    br i1 [[C_0]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    br i1 [[C_1]], label %[[THEN_2:.*]], label %[[ELSE]]
+; CHECK:       [[THEN_2]]:
+; CHECK-NEXT:    [[Q_INT:%.*]] = ptrtoint ptr [[Q]] to i64
+; CHECK-NEXT:    [[P_INT:%.*]] = ptrtoint ptr [[P]] to i64
+; CHECK-NEXT:    [[DIFF:%.*]] = sub i64 [[Q_INT]], [[P_INT]]
+; CHECK-NEXT:    [[DOUBLED:%.*]] = shl i64 [[DIFF]], 1
+; CHECK-NEXT:    ret i64 [[DOUBLED]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    ret i64 0
+;
+entry:
+  %p_int = ptrtoint ptr %p to i64
+  %q_int = ptrtoint ptr %q to i64
+  %diff = sub i64 %q_int, %p_int
+  br i1 %c.0, label %then, label %else
+
+then:
+  call void @llvm.assume(i1 true) [ "dereferenceable"(ptr %p, i64 %diff) ]
+  br i1 %c.1, label %then.2, label %else
+
+then.2:
+  %doubled = mul i64 %diff, 2
+  ret i64 %doubled
+
+else:
+  ret i64 0
+}
+
+define i64 @test_deref_user_does_not_dominate_other_user(ptr %p, ptr %q, i1 %c.0) {
+; CHECK-LABEL: define i64 @test_deref_user_does_not_dominate_other_user(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[Q:%.*]], i1 [[C_0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    br i1 [[C_0]], label %[[MIDDLE:.*]], label %[[EXIT:.*]]
+; CHECK:       [[MIDDLE]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[Q_INT:%.*]] = ptrtoint ptr [[Q]] to i64
+; CHECK-NEXT:    [[P_INT:%.*]] = ptrtoint ptr [[P]] to i64
+; CHECK-NEXT:    [[DIFF:%.*]] = sub i64 [[Q_INT]], [[P_INT]]
+; CHECK-NEXT:    ret i64 [[DIFF]]
+;
+entry:
+  %p_int = ptrtoint ptr %p to i64
+  %q_int = ptrtoint ptr %q to i64
+  %diff = sub i64 %q_int, %p_int
+  br i1 %c.0, label %middle, label %exit
+
+middle:
+  call void @llvm.assume(i1 true) [ "dereferenceable"(ptr %p, i64 %diff) ]
+  br label %exit
+
+exit:
+  ret i64 %diff
+}
+
 declare void @llvm.assume(i1 noundef)