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Fix roundtrip of affine.if #16

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Merged
merged 1 commit into from
Jun 19, 2020
Merged

Fix roundtrip of affine.if #16

merged 1 commit into from
Jun 19, 2020

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@flaub flaub commented Jun 19, 2020

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@flaub flaub requested a review from jbruestle June 19, 2020 18:44
@flaub flaub self-assigned this Jun 19, 2020
@flaub flaub merged commit 0451fe7 into plaidml/plaidml-v1 Jun 19, 2020
@flaub flaub deleted the flaub-fix-if branch June 19, 2020 19:27
haoyouab pushed a commit to Flex-plaidml-team/llvm-project that referenced this pull request Sep 4, 2020
When `Target::GetEntryPointAddress()` calls `exe_module->GetObjectFile()->GetEntryPointAddress()`, and the returned
`entry_addr` is valid, it can immediately be returned.

However, just before that, an `llvm::Error` value has been setup, but in this case it is not consumed before returning, like is done further below in the function.

In https://bugs.freebsd.org/248745 we got a bug report for this, where a very simple test case aborts and dumps core:

```
* thread plaidml#1, name = 'testcase', stop reason = breakpoint 1.1
    frame #0: 0x00000000002018d4 testcase`main(argc=1, argv=0x00007fffffffea18) at testcase.c:3:5
   1	int main(int argc, char *argv[])
   2	{
-> 3	    return 0;
   4	}
(lldb) p argc
Program aborted due to an unhandled Error:
Error value was Success. (Note: Success values must still be checked prior to being destroyed).

Thread 1 received signal SIGABRT, Aborted.
thr_kill () at thr_kill.S:3
3	thr_kill.S: No such file or directory.
(gdb) bt
#0  thr_kill () at thr_kill.S:3
plaidml#1  0x00000008049a0004 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52
plaidml#2  0x0000000804916229 in abort () at /usr/src/lib/libc/stdlib/abort.c:67
plaidml#3  0x000000000451b5f5 in fatalUncheckedError () at /usr/src/contrib/llvm-project/llvm/lib/Support/Error.cpp:112
plaidml#4  0x00000000019cf008 in GetEntryPointAddress () at /usr/src/contrib/llvm-project/llvm/include/llvm/Support/Error.h:267
plaidml#5  0x0000000001bccbd8 in ConstructorSetup () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:67
plaidml#6  0x0000000001bcd2c0 in ThreadPlanCallFunction () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:114
plaidml#7  0x00000000020076d4 in InferiorCallMmap () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp:97
plaidml#8  0x0000000001f4be33 in DoAllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSD/ProcessFreeBSD.cpp:604
plaidml#9  0x0000000001fe51b9 in AllocatePage () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:347
plaidml#10 0x0000000001fe5385 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:383
plaidml#11 0x0000000001974da2 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2301
plaidml#12 CanJIT () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2331
plaidml#13 0x0000000001a1bf3d in Evaluate () at /usr/src/contrib/llvm-project/lldb/source/Expression/UserExpression.cpp:190
plaidml#14 0x00000000019ce7a2 in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Target/Target.cpp:2372
plaidml#15 0x0000000001ad784c in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:414
plaidml#16 0x0000000001ad86ae in DoExecute () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:646
plaidml#17 0x0000000001a5e3ed in Execute () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandObject.cpp:1003
plaidml#18 0x0000000001a6c4a3 in HandleCommand () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:1762
plaidml#19 0x0000000001a6f98c in IOHandlerInputComplete () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2760
plaidml#20 0x0000000001a90b08 in Run () at /usr/src/contrib/llvm-project/lldb/source/Core/IOHandler.cpp:548
plaidml#21 0x00000000019a6c6a in ExecuteIOHandlers () at /usr/src/contrib/llvm-project/lldb/source/Core/Debugger.cpp:903
plaidml#22 0x0000000001a70337 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2946
plaidml#23 0x0000000001d9d812 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/API/SBDebugger.cpp:1169
plaidml#24 0x0000000001918be8 in MainLoop () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:675
plaidml#25 0x000000000191a114 in main () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:890```

Fix the incorrect error catch by only instantiating an `Error` object if it is necessary.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D86355
rengolin pushed a commit that referenced this pull request Nov 18, 2024
…xtend (llvm#105375)

GCC compiles the built-in function `__builtin_bswap16`, to the ARM
instruction rev16, which reverses the byte order of 16-bit data. On the
other Clang compiles the same built-in function to e.g.
```     
        rev     w8, w0
        lsr     w0, w8, #16
```
i.e. it performs a byte reversal of a 32-bit register, (which moves the
lower half, which contains the 16-bit data, to the upper half) and then
right shifts the reversed 16-bit data back to the lower half of the
register.
We can improve Clang codegen by generating `rev16` instead of `rev` and
`lsr`, like GCC.
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