[llvm] [DTLTO][LLVM] Integrated Distributed ThinLTO (DTLTO) (PR #127749)

[via llvm-commits]

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+; Check that the JSON output from DTLTO is as expected. Note that validate.py
+; checks the JSON structure so we just check the field contents in this test.
+
+RUN: rm -rf %t && split-file %s %t && cd %t
+
+; Generate bitcode files with summary.
+RUN: opt -thinlto-bc t1.ll -o t1.bc
+RUN: opt -thinlto-bc t2.ll -o t2.bc
+
+; Perform DTLTO.
+RUN: not llvm-lto2 run t1.bc t2.bc -o my.output \
+RUN:     -r=t1.bc,t1,px -r=t2.bc,t2,px \
+RUN:     -dtlto-distributor=%python \
+RUN:     -thinlto-distributor-arg=%llvm_src_root/utils/dtlto/validate.py \
+RUN:     -thinlto-remote-compiler=my_clang.exe \
+RUN:     -thinlto-remote-compiler-arg=--rota1=10 \
+RUN:     -thinlto-remote-compiler-arg=--rota2=20 \
+RUN:     -thinlto-distributor-arg=--da1=10 \
+RUN:     -thinlto-distributor-arg=--da2=10 \
+RUN:   2>&1 | FileCheck %s
+
+CHECK: distributor_args=['--da1=10', '--da2=10']
+
+; Check the common object.
+CHECK:      "linker_output": "my.output"
+CHECK:      "args":
+CHECK:      "my_clang.exe"
+CHECK:      "-o"
+CHECK-NEXT: [
+CHECK-NEXT: "primary_output"
+CHECK-NEXT: 0
+CHECK-NEXT: ]
+CHECK:      "-c"
+CHECK:      "-x"
+CHECK:      "ir"
+CHECK-NEXT: [
+CHECK-NEXT: "primary_input"
+CHECK-NEXT:  0
+CHECK-NEXT: ]
+CHECK:      "summary_index"
+CHECK-NEXT: "-fthinlto-index="
+CHECK-NEXT: 0
+CHECK-NEXT: ]
+CHECK:      "--target=x86_64-unknown-linux-gnu"
+CHECK:      "-O2",
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bd1976bris wrote:

Using -mllvm options was a nice reduction in the number of changes required in different tools, which was helpful to reduce the size of the initial PR. However, I think there is agreement now that proper options are required. Note that we don't have to update all the LLD ports at once. We can add DTLTO support to the different LLD ports incrementally. Perhaps we can start with just the ELF LLD port (chosen as it is the LLD port I'm most familiar with)?

https://github.com/llvm/llvm-project/pull/127749