Fix QPainter non-determinism on macOS (0.21 backport) #20479
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Aplies a patch to Qt that fixes the non-determinism by modifying Qt. The source of the non-determinism is how LLVM 8 optimizes qt_intersect_spans when compiling. The particular optimization that seems to be causing the problems is that a temp variable is being added for spans->y. For some reason, when it does this, it chooses different instructions to use when making that variable. We bypass this problem by patching qt_intersect_spans to always make and use this local variable. Github-Pull: bitcoin#20447 Rebased-From: 8f7d1b3 Tree-SHA512: 558da5c2bb0373e2a89f2c219170f802036e0e87cc8e808336b23d074152cb893007a440f46ec957156b0921355cd18502710f2d224f27bc26e934c50ebebc41
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Thanks. |
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ACK ab23a83 |
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fwiw this is my gitian output for commit ab23a83: |
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I have different gitian results: @laanwj Did you clean the cache before building? |
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No, I did not clean the cache before building. Will try… |
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Unfortunately I still get the same output after cleaning my cache (deleting |
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I'm seeing the same result as @laanwj: Generating report
9df7d246f4b55910bd97aa5b010f78d5c9ffd7ca44950230df39a22205d7fe2f bitcoin-ab23a83400d5-osx-unsigned.dmg
5a51563c3bf09248f5bce66a690a1773e964d649c45b6f6aaf82748fa5caff7d bitcoin-ab23a83400d5-osx-unsigned.tar.gz
d894452b461b9b9e779b6868a0c1d9ea0c33339694470646082234217ddcc05d bitcoin-ab23a83400d5-osx64.tar.gz
d671af2ac2b9ec021c1cbb4614209b504d5bb4e1b1ddc922c7f0adcd99f529b6 src/bitcoin-ab23a83400d5.tar.gz
4dc65a795df2c40c086ddcc76990d9c623325480a0b30e59b12157289a881180 bitcoin-core-osx-0.21-res.yml |
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Same here: |
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Cleaned up everything and now I get the matching result: |
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Aplies a patch to Qt that fixes the non-determinism by modifying Qt. The
source of the non-determinism is how LLVM 8 optimizes qt_intersect_spans
when compiling. The particular optimization that seems to be causing the
problems is that a temp variable is being added for spans->y. For some
reason, when it does this, it chooses different instructions to use when
making that variable. We bypass this problem by patching
qt_intersect_spans to always make and use this local variable.
Github-Pull: #20447
Rebased-From: 8f7d1b3
Tree-SHA512: 558da5c2bb0373e2a89f2c219170f802036e0e87cc8e808336b23d074152cb893007a440f46ec957156b0921355cd18502710f2d224f27bc26e934c50ebebc41