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71 lines
3.0 KiB
71 lines
3.0 KiB
From d0ff02e567541468309923fed2320da6cbd81779 Mon Sep 17 00:00:00 2001 |
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From: Ben Crocker <bcrocker@redhat.com> |
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Date: Thu, 21 Nov 2019 17:33:31 -0500 |
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Subject: [PATCH] llvmpipe: use ppc64le/ppc64 Large code model for JIT-compiled |
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shaders |
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Large programs, e.g. gnome-shell and firefox, may tax the |
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addressability of the Medium code model once a (potentially unbounded) |
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number of dynamically generated JIT-compiled shader programs are |
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linked in and relocated. Yet the default code model as of LLVM 8 is |
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Medium or even Small. |
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The cost of changing from Medium to Large is negligible: |
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- an additional 8-byte pointer stored immediately before the shader entrypoint; |
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- change an add-immediate (addis) instruction to a load (ld). |
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Testing with WebGL Conformance |
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(https://www.khronos.org/registry/webgl/sdk/tests/webgl-conformance-tests.html) |
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yields clean runs with this change (and crashes without it). |
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Testing with glxgears shows no detectable performance difference. |
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Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1753327, 1543572, 1747110, and 1582226 |
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Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/223 |
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Co-authored by: Nemanja Ivanovic <nemanjai@ca.ibm.com>, Tom Stellard <tstellar@redhat.com> |
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CC: mesa-stable@lists.freedesktop.org |
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Signed-off-by: Ben Crocker <bcrocker@redhat.com> |
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Reviewed-by: Adam Jackson <ajax@redhat.com> |
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--- |
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src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 15 ++++++++++++++- |
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1 file changed, 14 insertions(+), 1 deletion(-) |
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diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp |
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--- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp |
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+++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp |
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@@ -686,7 +686,19 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT, |
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* when not using MCJIT so no instructions are generated which the old JIT |
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* can't handle. Not entirely sure if we really need to do anything yet. |
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*/ |
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-#if defined(PIPE_ARCH_LITTLE_ENDIAN) && defined(PIPE_ARCH_PPC_64) |
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+#ifdef PIPE_ARCH_PPC_64 |
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+ /* |
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+ * Large programs, e.g. gnome-shell and firefox, may tax the addressability |
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+ * of the Medium code model once dynamically generated JIT-compiled shader |
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+ * programs are linked in and relocated. Yet the default code model as of |
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+ * LLVM 8 is Medium or even Small. |
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+ * The cost of changing from Medium to Large is negligible: |
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+ * - an additional 8-byte pointer stored immediately before the shader entrypoint; |
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+ * - change an add-immediate (addis) instruction to a load (ld). |
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+ */ |
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+ builder.setCodeModel(CodeModel::Large); |
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+ |
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+#ifdef PIPE_ARCH_LITTLE_ENDIAN |
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/* |
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* Versions of LLVM prior to 4.0 lacked a table entry for "POWER8NVL", |
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* resulting in (big-endian) "generic" being returned on |
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@@ -698,6 +710,7 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT, |
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*/ |
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if (MCPU == "generic") |
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MCPU = "pwr8"; |
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+#endif |
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#endif |
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builder.setMCPU(MCPU); |
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if (gallivm_debug & (GALLIVM_DEBUG_IR | GALLIVM_DEBUG_ASM | GALLIVM_DEBUG_DUMP_BC)) { |
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-- |
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2.21.0 |
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