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test/Transforms/InstCombine/str-int.ll | ||
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7 | @strtol_dec? | |
11 | Needs negative test with endptr not being null. | |
12 | Do we care about the return type here? | |
17 | I'd like to see one test with base = 0. | |
19 | I'm not sure these ; Function Attrs comments are needed. | |
20 | @strtol_hex? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1718 |
I'm guessing you want to check the third operand here, not the second one. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1722 | Oh, CI is CallInst, not ConstantInt, never mind then. | |
test/Transforms/InstCombine/str-int.ll | ||
6 | The STRTOL(3) says that strtol returns long int, so it would still be good for the tests to represent that. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1708 | Both of these getConstantStringInfo() == false are also not covered with tests, i think? | |
1721 | You also probably want a negative test with this third operand being not a constant (an argument of the test function) | |
test/Transforms/InstCombine/str-int-2.ll | ||
5 | But this is just 1<<31, it fits into i32 as-is. | |
7 | I'm not sure why you need to separate it into two test files? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1710 | I'm worried about host behavior leaking through here; specifically, the "undefined" values for overflow might vary. Could you use some function with more predictable behavior here? (Maybe something based on llvm::consumeSignedInteger()?) | |
1722 | This is missing some checks. In particular, what happens if the host's "long" is a different width from the target's "long"? What happens if strtol sets errno? What happens if the target program is using a locale where isspace() doesn't match the C locale's isspace()? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1722 | I dont know about that thing with locale. I dont think we have to care about this weirdness. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1722 | isspace() in all locales should return true for all the characters where it returns true in the C locale; it's just a question of whether there are some additional characters which also count as spaces. So I think you'll get the right behavior if you refuse to fold in cases where strtol would fail in the C locale. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1722 | The result of strtol("2147483648", 0, 0) varies depending on whether long is 32 bits or 64 bits. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1710 | I guess we can just call strtol, sure. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1710 | So now is this patch good to go? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1710 | You didn't actually change the code to call strtol instead of atoi. | |
1735 | DL.getTypeAllocSize(CI->getType()) != sizeof(long int) will cause your testcase to fail on 32-bit hosts (because we'll refuse the fold the call). Can you use strtoll plus a range check, instead? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | But problem is .. errs() << std::numeric_limits<long int>::max() << "\n"; 9223372036854775807 So we need to rely on errno, I think |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | By "range check", I mean in addition to the errno check, if CI->getType() is a 32-bit integer, check that the result of strtoll fits into a 32-bit integer. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | Oh :D ok. Will fix. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | The range check is still wrong. You can try building 32-bit LLVM yourself by setting the CMake option LLVM_BUILD_32_BITS. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | So how to fix it? |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | I have no idea what I should do to fix it... :/ |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | I think the most readable solution is something like int Bits = CI->getType()->getPrimitiveSizeInBits(); if (Result < llvm::minIntN(Bits) || Result > llvm::maxIntN(Bits)) return nullptr;. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | Actually, you can simplify that to just if (!isIntN(CI->getType()->getPrimitiveSizeInBits(), Result)) return nullptr;. |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1735 | Thank you so much! (I have no idea about that API) |
@efriedma , is now everything ok?
I would send some more patches for SimplifyLibCalls where I would like to use newly introduced isCLocale function.
I'd like to see a second testcase which checks our transforms on declare i32 @strtol(i8*, i8**, i32) (which is the signature on 32-bit targets).
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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108 | We can safely assume nobody is messing with the locale in the compiler itself. The problem comes when someone uses setlocale on the target (in the compiled program); that's not something you can detect in general. Fortunately, we can still handle the interesting cases, I think: if we assume all possible target locales are ASCII supersets, or something close (which we already assume in other places), then if strtoll successfully parses a number on the host (i.e. nptr != endptr), it will also successfully parse the same way on the target. If the string starts with a non-ASCII character, we probably have to assume it could be a space in some locale. | |
1721 | Can you just return Result here, instead of calling atoi? | |
1739 | strtoll can also fail with EINVAL, if the base is invalid. But the exact behavior isn't specified in the C standard, so probably better to check the base ourselves, explicitly. | |
2325 | Can you also add cases here for atol, atoll, and strtoll? (Your current implementations should just work.) |
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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2325 | Maybe one test each to make sure we recognize the names, and a test to make sure 64-bit atoll actually allows inputs greater than 2**32; we don't need all the tests for each one given the code is the same. |
Added tests for atol, atoll, strtoll.
lib/Transforms/Utils/SimplifyLibCalls.cpp | ||
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1742 | :) Ahh |
It's better to ask someone who looked at this patch to commit it; I didn't follow this review this at all.
Ok, I was not sure if @efriedma can merge it since I see you merge patches every day in the "InstCombine" part. Sorry then :)
I was going to commit this, but then I discovered that str-int.ll and str-int-2.ll are identical. Did you accidentally overwrite your changes?
We can safely assume nobody is messing with the locale in the compiler itself. The problem comes when someone uses setlocale on the target (in the compiled program); that's not something you can detect in general.
Fortunately, we can still handle the interesting cases, I think: if we assume all possible target locales are ASCII supersets, or something close (which we already assume in other places), then if strtoll successfully parses a number on the host (i.e. nptr != endptr), it will also successfully parse the same way on the target. If the string starts with a non-ASCII character, we probably have to assume it could be a space in some locale.