forked from OSchip/llvm-project
fc4b3951e9
Summary:
By removing FeatureNoARM implies ModeThumb, we can detect cases where a
function's target-features contain -thumb-mode (enables ARM codegen for the
function), but the architecture does not support ARM mode. Previously, the
implication caused the FeatureNoARM bit to be cleared for functions with
-thumb-mode, making the assertion in ARMSubtarget::ARMSubtarget [1]
pointless for such functions.
This assertion is the only guard against generating ARM code for
architectures without ARM codegen support. Is there a place where we
could easily generate error messages for the user? At the moment, we
would generate ARM code for Thumb-only architectures. X86 has the same
behavior as ARM, as in it only has an assertion and no error message,
but I think for ARM an error message would be helpful. What do you
think?
For the example below, `llc -mtriple=armv7m-eabi test.ll -o -` will
generate ARM assembler (or fail with an assertion error with this patch).
Note that if we run the resulting assembler through llvm-mc, we get
an appropriate error message, but not when codegen is handled
through clang.
```
define void @bar() #0 {
entry:
ret void
}
attributes #0 = { "target-features"="-thumb-mode" }
```
[1]
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||
|---|---|---|
| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llgo | ||
| llvm | ||
| openmp | ||
| parallel-libs | ||
| polly | ||