47 lines
2.0 KiB
Makefile
47 lines
2.0 KiB
Makefile
# needs-profiler-support
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# ignore-windows-gnu
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# FIXME(mati865): MinGW GCC miscompiles compiler-rt profiling library but with Clang it works
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# properly. Since we only have GCC on the CI ignore the test for now.
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include ../tools.mk
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# This test makes sure that PGO profiling data leads to cold functions being
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# marked as `cold` and hot functions with `inlinehint`.
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# The test program contains an `if` were actual execution only ever takes the
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# `else` branch. Accordingly, we expect the function that is never called to
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# be marked as cold.
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#
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# Disable the pre-inlining pass (i.e. a pass that does some inlining before
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# it adds the profiling instrumentation). Disabling this pass leads to
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# rather predictable IR which we need for this test to be stable.
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COMMON_FLAGS=-Copt-level=2 -Ccodegen-units=1 -Cllvm-args=-disable-preinline
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ifeq ($(UNAME),Darwin)
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# macOS does not have the `tac` command, but `tail -r` does the same thing
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TAC := tail -r
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else
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# some other platforms don't support the `-r` flag for `tail`, so use `tac`
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TAC := tac
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endif
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all:
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# Compile the test program with instrumentation
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$(RUSTC) $(COMMON_FLAGS) -Cprofile-generate="$(TMPDIR)" main.rs
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# Run it in order to generate some profiling data
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$(call RUN,main some-argument) || exit 1
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# Postprocess the profiling data so it can be used by the compiler
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"$(LLVM_BIN_DIR)"/llvm-profdata merge \
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-o "$(TMPDIR)"/merged.profdata \
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"$(TMPDIR)"/default_*.profraw
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# Compile the test program again, making use of the profiling data
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$(RUSTC) $(COMMON_FLAGS) -Cprofile-use="$(TMPDIR)"/merged.profdata --emit=llvm-ir main.rs
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# Check that the generate IR contains some things that we expect
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#
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# We feed the file into LLVM FileCheck tool *in reverse* so that we see the
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# line with the function name before the line with the function attributes.
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# FileCheck only supports checking that something matches on the next line,
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# but not if something matches on the previous line.
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$(TAC) "$(TMPDIR)"/main.ll | "$(LLVM_FILECHECK)" filecheck-patterns.txt
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