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llvm-project/llvm/test/Verifier/alias.ll

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Reject alias to undefined symbols in the verifier. On ELF and COFF an alias is just another name for a position in the file. There is no way to refer to a position in another file, so an alias to undefined is meaningless. MachO currently doesn't support aliases. The spec has a N_INDR, which when implemented will have a different set of restrictions. Adding support for it shouldn't be harder than any other IR extension. For now, having the IR represent what is actually possible with current tools makes it easier to fix the design of GlobalAlias. llvm-svn: 203705
2014-03-13 04:15:49 +08:00
; RUN: not llvm-as %s -o /dev/null 2>&1 | FileCheck %s
declare void @f()
[opaque pointer type] Add textual IR support for explicit type parameter for global aliases update.py: import fileinput import sys import re alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias" plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)") cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)") gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)") def conv(line): m = re.match(cast, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(gep, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(plain, line) if m: return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n" return line for line in sys.stdin: sys.stdout.write(conv(line)) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh llvm-svn: 247378
2015-09-11 11:22:04 +08:00
@fa = alias void (), void ()* @f
Reject alias to undefined symbols in the verifier. On ELF and COFF an alias is just another name for a position in the file. There is no way to refer to a position in another file, so an alias to undefined is meaningless. MachO currently doesn't support aliases. The spec has a N_INDR, which when implemented will have a different set of restrictions. Adding support for it shouldn't be harder than any other IR extension. For now, having the IR represent what is actually possible with current tools makes it easier to fix the design of GlobalAlias. llvm-svn: 203705
2014-03-13 04:15:49 +08:00
; CHECK: Alias must point to a definition
; CHECK-NEXT: @fa
@g = external global i32
[opaque pointer type] Add textual IR support for explicit type parameter for global aliases update.py: import fileinput import sys import re alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias" plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)") cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)") gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)") def conv(line): m = re.match(cast, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(gep, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(plain, line) if m: return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n" return line for line in sys.stdin: sys.stdout.write(conv(line)) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh llvm-svn: 247378
2015-09-11 11:22:04 +08:00
@ga = alias i32, i32* @g
Reject alias to undefined symbols in the verifier. On ELF and COFF an alias is just another name for a position in the file. There is no way to refer to a position in another file, so an alias to undefined is meaningless. MachO currently doesn't support aliases. The spec has a N_INDR, which when implemented will have a different set of restrictions. Adding support for it shouldn't be harder than any other IR extension. For now, having the IR represent what is actually possible with current tools makes it easier to fix the design of GlobalAlias. llvm-svn: 203705
2014-03-13 04:15:49 +08:00
; CHECK: Alias must point to a definition
; CHECK-NEXT: @ga
Allow alias to point to an arbitrary ConstantExpr. This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32*) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char *". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. llvm-svn: 210062
2014-06-03 10:41:57 +08:00
Disallow aliases to available_externally. They are as much trouble as aliases to declarations. They are requiring the code generator to define a symbol with the same value as another symbol, but the second symbol is undefined. If representing this is important for some optimization, we could add support for available_externally aliases. They would be *required* to point to a declaration (or available_externally definition). llvm-svn: 254170
2015-11-27 03:22:59 +08:00
define available_externally void @f2() {
ret void
}
@fa2 = alias void(), void()* @f2
; CHECK: Alias must point to a definition
; CHECK-NEXT: @fa2
Allow alias to point to an arbitrary ConstantExpr. This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32*) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char *". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. llvm-svn: 210062
2014-06-03 10:41:57 +08:00
[opaque pointer type] Add textual IR support for explicit type parameter for global aliases update.py: import fileinput import sys import re alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias" plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)") cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)") gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)") def conv(line): m = re.match(cast, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(gep, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(plain, line) if m: return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n" return line for line in sys.stdin: sys.stdout.write(conv(line)) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh llvm-svn: 247378
2015-09-11 11:22:04 +08:00
@test2_a = alias i32, i32* @test2_b
@test2_b = alias i32, i32* @test2_a
Allow alias to point to an arbitrary ConstantExpr. This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32*) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char *". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. llvm-svn: 210062
2014-06-03 10:41:57 +08:00
; CHECK: Aliases cannot form a cycle
; CHECK-NEXT: i32* @test2_a
; CHECK-NEXT: Aliases cannot form a cycle
; CHECK-NEXT: i32* @test2_b
@test3_a = global i32 42
[opaque pointer type] Add textual IR support for explicit type parameter for global aliases update.py: import fileinput import sys import re alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias" plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)") cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)") gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)") def conv(line): m = re.match(cast, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(gep, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(plain, line) if m: return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n" return line for line in sys.stdin: sys.stdout.write(conv(line)) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh llvm-svn: 247378
2015-09-11 11:22:04 +08:00
@test3_b = weak alias i32, i32* @test3_a
@test3_c = alias i32, i32* @test3_b
Don't IPO over functions that can be de-refined Summary: Fixes PR26774. If you're aware of the issue, feel free to skip the "Motivation" section and jump directly to "This patch". Motivation: I define "refinement" as discarding behaviors from a program that the optimizer has license to discard. So transforming: ``` void f(unsigned x) { unsigned t = 5 / x; (void)t; } ``` to ``` void f(unsigned x) { } ``` is refinement, since the behavior went from "if x == 0 then undefined else nothing" to "nothing" (the optimizer has license to discard undefined behavior). Refinement is a fundamental aspect of many mid-level optimizations done by LLVM. For instance, transforming `x == (x + 1)` to `false` also involves refinement since the expression's value went from "if x is `undef` then { `true` or `false` } else { `false` }" to "`false`" (by definition, the optimizer has license to fold `undef` to any non-`undef` value). Unfortunately, refinement implies that the optimizer cannot assume that the implementation of a function it can see has all of the behavior an unoptimized or a differently optimized version of the same function can have. This is a problem for functions with comdat linkage, where a function can be replaced by an unoptimized or a differently optimized version of the same source level function. For instance, FunctionAttrs cannot assume a comdat function is actually `readnone` even if it does not have any loads or stores in it; since there may have been loads and stores in the "original function" that were refined out in the currently visible variant, and at the link step the linker may in fact choose an implementation with a load or a store. As an example, consider a function that does two atomic loads from the same memory location, and writes to memory only if the two values are not equal. The optimizer is allowed to refine this function by first CSE'ing the two loads, and the folding the comparision to always report that the two values are equal. Such a refined variant will look like it is `readonly`. However, the unoptimized version of the function can still write to memory (since the two loads //can// result in different values), and selecting the unoptimized version at link time will retroactively invalidate transforms we may have done under the assumption that the function does not write to memory. Note: this is not just a problem with atomics or with linking differently optimized object files. See PR26774 for more realistic examples that involved neither. This patch: This change introduces a new set of linkage types, predicated as `GlobalValue::mayBeDerefined` that returns true if the linkage type allows a function to be replaced by a differently optimized variant at link time. It then changes a set of IPO passes to bail out if they see such a function. Reviewers: chandlerc, hfinkel, dexonsmith, joker.eph, rnk Subscribers: mcrosier, llvm-commits Differential Revision: http://reviews.llvm.org/D18634 llvm-svn: 265762
2016-04-08 08:48:30 +08:00
; CHECK: Alias cannot point to an interposable alias
Allow alias to point to an arbitrary ConstantExpr. This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32*) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char *". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. llvm-svn: 210062
2014-06-03 10:41:57 +08:00
; CHECK-NEXT: i32* @test3_c