handle inbounds

Author: nikic

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -2655,8 +2655,11 @@ static Instruction *canonicalizeGEPOfConstGEPI8(GetElementPtrInst &GEP,
     GEPNoWrapFlags Flags = GEPNoWrapFlags::none();
     if (GEP.hasNoUnsignedWrap() &&
         cast<GEPOperator>(Src)->hasNoUnsignedWrap() &&
-        match(GEP.getOperand(1), m_NUWAddLike(m_Value(), m_Value())))
+        match(GEP.getOperand(1), m_NUWAddLike(m_Value(), m_Value()))) {
       Flags |= GEPNoWrapFlags::noUnsignedWrap();
+      if (GEP.isInBounds() && cast<GEPOperator>(Src)->isInBounds())
+        Flags |= GEPNoWrapFlags::inBounds();
+    }
 
     Value *GEPConst =
         IC.Builder.CreatePtrAdd(Base, IC.Builder.getInt(NewOffset), "", Flags);

llvm/test/Transforms/InstCombine/gepofconstgepi8.ll

@@ -368,3 +368,108 @@ entry:
   %p2 = getelementptr nuw i32, ptr %p1, i64 %index
   ret ptr %p2
 }
+
+define ptr @test_all_inbounds_nuw(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_inbounds_nuw(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds nuw i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr inbounds nuw i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr inbounds nuw i8, ptr %base, i64 1
+  %index = add nuw i64 %a, 2
+  %p2 = getelementptr inbounds nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_partial_inbounds1(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_partial_inbounds1(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr nuw i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr nuw i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr nuw i8, ptr %base, i64 1
+  %index = add nuw i64 %a, 2
+  %p2 = getelementptr inbounds nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_partial_inbounds2(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_partial_inbounds2(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr nuw i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr nuw i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr inbounds nuw i8, ptr %base, i64 1
+  %index = add nuw i64 %a, 2
+  %p2 = getelementptr nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_inbounds_partial_nuw1(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_inbounds_partial_nuw1(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr [[BASE]], i64 7
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr inbounds i8, ptr %base, i64 -1
+  %index = add nuw i64 %a, 2
+  %p2 = getelementptr inbounds nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_inbounds_partial_nuw2(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_inbounds_partial_nuw2(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr inbounds nuw i8, ptr %base, i64 1
+  %index = add nuw i64 %a, 2
+  %p2 = getelementptr inbounds i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_inbounds_partial_nuw3(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_inbounds_partial_nuw3(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr inbounds nuw i8, ptr %base, i64 1
+  %index = add i64 %a, 2
+  %p2 = getelementptr inbounds nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}
+
+define ptr @test_all_nusw_nuw(ptr %base, i64 %a) {
+; CHECK-LABEL: define ptr @test_all_nusw_nuw(
+; CHECK-SAME: ptr [[BASE:%.*]], i64 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr nuw i8, ptr [[BASE]], i64 9
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr nuw i32, ptr [[TMP0]], i64 [[A]]
+; CHECK-NEXT:    ret ptr [[P2]]
+;
+entry:
+  %p1 = getelementptr nusw nuw i8, ptr %base, i64 1
+  %index = add nsw nuw i64 %a, 2
+  %p2 = getelementptr nusw nuw i32, ptr %p1, i64 %index
+  ret ptr %p2
+}