[InstSimplify] Add a test for current get/set intrinsic folding

Author: arichardson

llvm/test/Transforms/InstSimplify/cheri-intrinsics-get-set.ll

@@ -0,0 +1,296 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes --force-update
+;; Check folds for CHERI intrinsics that have both get and set variants
+; RUN: sed 's/FIELD/address/' %s | opt -S -passes=instsimplify | FileCheck %s --check-prefixes=ADDRESS
+; RUN: sed 's/FIELD/flags/' %s | opt -S -passes=instsimplify | FileCheck %s --check-prefixes=FLAGS
+; RUN: sed 's/FIELD/high/' %s | opt -S -passes=instsimplify | FileCheck %s --check-prefixes=HIGH
+; RUN: sed 's/FIELD/offset/' %s | opt -S -passes=instsimplify | FileCheck %s --check-prefixes=OFFSET
+target datalayout = "pf200:128:128:128:64-A200-P200-G200"
+
+declare i64 @check_fold(i64) nounwind
+declare i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200)) nounwind
+declare ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200), i64) nounwind
+
+
+;; This is a no-op and should be folded to ret %arg
+define ptr addrspace(200) @fold_set_of_get(ptr addrspace(200) %arg) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_set_of_get
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[ARG]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_set_of_get
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+; FLAGS-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.flags.get.i64(ptr addrspace(200) [[ARG]])
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_set_of_get
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+; HIGH-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) [[ARG]])
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_set_of_get
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+; OFFSET-NEXT:    ret ptr addrspace(200) [[ARG]]
+;
+  %value = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) %arg)
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %arg, i64 %value)
+  ret ptr addrspace(200) %ret
+}
+
+;; negative test - get of a different value should not be folded to ret %arg
+define ptr addrspace(200) @fold_set_of_get_bad(ptr addrspace(200) %arg, ptr addrspace(200) %other) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_set_of_get_bad
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.address.get.i64(ptr addrspace(200) [[OTHER]])
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_set_of_get_bad
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.flags.get.i64(ptr addrspace(200) [[OTHER]])
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_set_of_get_bad
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) [[OTHER]])
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_set_of_get_bad
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[VALUE:%.*]] = tail call i64 @llvm.cheri.cap.offset.get.i64(ptr addrspace(200) [[OTHER]])
+; OFFSET-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; OFFSET-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+  %value = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) %other)
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %arg, i64 %value)
+  ret ptr addrspace(200) %ret
+}
+
+;; For almost all intrinsics this get-of-set pair can be elided
+;; NB: This is not true for flags where the value written by set could be truncated to another value
+;; FIXME: high.get should be folded.
+define i64 @fold_get_of_set(ptr addrspace(200) %arg, i64 %value) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_get_of_set
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    ret i64 [[VALUE]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_get_of_set
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; FLAGS-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.flags.get.i64(ptr addrspace(200) [[MODIFIED]])
+; FLAGS-NEXT:    ret i64 [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_get_of_set
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; HIGH-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) [[MODIFIED]])
+; HIGH-NEXT:    ret i64 [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_get_of_set
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    ret i64 [[VALUE]]
+;
+  %modified = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %arg, i64 %value)
+  %ret = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) %modified)
+  ret i64 %ret
+}
+
+;; Negative test -- get is used on other intrinsic
+define i64 @fold_get_of_set_bad(ptr addrspace(200) %arg, ptr addrspace(200) %other, i64 %value) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_get_of_set_bad
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.address.get.i64(ptr addrspace(200) [[ARG]])
+; ADDRESS-NEXT:    ret i64 [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_get_of_set_bad
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.flags.get.i64(ptr addrspace(200) [[ARG]])
+; FLAGS-NEXT:    ret i64 [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_get_of_set_bad
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) [[ARG]])
+; HIGH-NEXT:    ret i64 [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_get_of_set_bad
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]], ptr addrspace(200) [[OTHER:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.offset.get.i64(ptr addrspace(200) [[ARG]])
+; OFFSET-NEXT:    ret i64 [[RET]]
+;
+  %modified = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %other, i64 %value)
+  %ret = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) %arg)
+  ret i64 %ret
+}
+
+define i64 @fold_get_on_null() nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_get_on_null
+; ADDRESS-SAME: () addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    ret i64 0
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_get_on_null
+; FLAGS-SAME: () addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    ret i64 0
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_get_on_null
+; HIGH-SAME: () addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) null)
+; HIGH-NEXT:    ret i64 [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_get_on_null
+; OFFSET-SAME: () addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    ret i64 0
+;
+  %ret = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) null)
+  ret i64 %ret
+}
+
+define i64 @fold_get_on_null_with_gep(i64 %value, i64 %gepoff) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_get_on_null_with_gep
+; ADDRESS-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    ret i64 [[GEPOFF]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_get_on_null_with_gep
+; FLAGS-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    ret i64 0
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_get_on_null_with_gep
+; HIGH-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[TMP:%.*]] = getelementptr i8, ptr addrspace(200) null, i64 [[GEPOFF]]
+; HIGH-NEXT:    [[RET:%.*]] = tail call i64 @llvm.cheri.cap.high.get.i64(ptr addrspace(200) [[TMP]])
+; HIGH-NEXT:    ret i64 [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_get_on_null_with_gep
+; OFFSET-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    ret i64 [[GEPOFF]]
+;
+  %tmp = getelementptr i8, ptr addrspace(200) null, i64 %gepoff
+  %ret = tail call i64 @llvm.cheri.cap.FIELD.get.i64(ptr addrspace(200) %tmp)
+  ret i64 %ret
+}
+
+;; TODO: Setting is idempotent, so the first call should be elided
+define ptr addrspace(200) @set_idempotent(ptr addrspace(200) %arg, i64 %value) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@set_idempotent
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@set_idempotent
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@set_idempotent
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@set_idempotent
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; OFFSET-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; OFFSET-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+  %modified = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %arg, i64 %value)
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %modified, i64 %value)
+  ret ptr addrspace(200) %ret
+}
+
+
+;; Negative test - calls with the same base argument are not yet elided if the
+;; second argument is different since they could have side-effects such as
+;; clearing the tag. For example `setoffset(setoffset(x, <LARGE>), <SMALL>)`
+;; would result in an untagged value if the first setoffset went outside the
+;; representable range but that detagging would not happen if we elide it.
+;; TODO: Maybe we should do this fold since people should not be relying on
+;; representability to clear tags of capabilities.
+define ptr addrspace(200) @set_different_values(ptr addrspace(200) %arg, i64 %value, i64 %value2) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@set_different_values
+; ADDRESS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]], i64 [[VALUE2:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@set_different_values
+; FLAGS-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]], i64 [[VALUE2:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@set_different_values
+; HIGH-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]], i64 [[VALUE2:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@set_different_values
+; OFFSET-SAME: (ptr addrspace(200) [[ARG:%.*]], i64 [[VALUE:%.*]], i64 [[VALUE2:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[MODIFIED:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[ARG]], i64 [[VALUE]])
+; OFFSET-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[MODIFIED]], i64 [[VALUE]])
+; OFFSET-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+  %modified = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %arg, i64 %value)
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %modified, i64 %value)
+  ret ptr addrspace(200) %ret
+}
+
+define ptr addrspace(200) @fold_set_on_null(i64 %value) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_set_on_null
+; ADDRESS-SAME: (i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) null, i64 [[VALUE]])
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_set_on_null
+; FLAGS-SAME: (i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) null, i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_set_on_null
+; HIGH-SAME: (i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) null, i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_set_on_null
+; OFFSET-SAME: (i64 [[VALUE:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) null, i64 [[VALUE]])
+; OFFSET-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) null, i64 %value)
+  ret ptr addrspace(200) %ret
+}
+
+define ptr addrspace(200) @fold_set_on_null_with_gep(i64 %value, i64 %gepoff) nounwind {
+; ADDRESS-LABEL: define {{[^@]+}}@fold_set_on_null_with_gep
+; ADDRESS-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; ADDRESS-NEXT:    [[TMP:%.*]] = getelementptr i8, ptr addrspace(200) null, i64 [[GEPOFF]]
+; ADDRESS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.address.set.i64(ptr addrspace(200) [[TMP]], i64 [[VALUE]])
+; ADDRESS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; FLAGS-LABEL: define {{[^@]+}}@fold_set_on_null_with_gep
+; FLAGS-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; FLAGS-NEXT:    [[TMP:%.*]] = getelementptr i8, ptr addrspace(200) null, i64 [[GEPOFF]]
+; FLAGS-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.flags.set.i64(ptr addrspace(200) [[TMP]], i64 [[VALUE]])
+; FLAGS-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; HIGH-LABEL: define {{[^@]+}}@fold_set_on_null_with_gep
+; HIGH-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; HIGH-NEXT:    [[TMP:%.*]] = getelementptr i8, ptr addrspace(200) null, i64 [[GEPOFF]]
+; HIGH-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.high.set.i64(ptr addrspace(200) [[TMP]], i64 [[VALUE]])
+; HIGH-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+; OFFSET-LABEL: define {{[^@]+}}@fold_set_on_null_with_gep
+; OFFSET-SAME: (i64 [[VALUE:%.*]], i64 [[GEPOFF:%.*]]) addrspace(200) #[[ATTR0]] {
+; OFFSET-NEXT:    [[TMP:%.*]] = getelementptr i8, ptr addrspace(200) null, i64 [[GEPOFF]]
+; OFFSET-NEXT:    [[RET:%.*]] = tail call ptr addrspace(200) @llvm.cheri.cap.offset.set.i64(ptr addrspace(200) [[TMP]], i64 [[VALUE]])
+; OFFSET-NEXT:    ret ptr addrspace(200) [[RET]]
+;
+  %tmp = getelementptr i8, ptr addrspace(200) null, i64 %gepoff
+  %ret = tail call ptr addrspace(200) @llvm.cheri.cap.FIELD.set.i64(ptr addrspace(200) %tmp, i64 %value)
+  ret ptr addrspace(200) %ret
+}