Revert "[llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported instructions fixed (#136868)" #142382
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…d instructions fixed (llvm#136868)" This reverts commit 475531b. But it does not revert the changes from commits 36850a0 and 5dc3cd0.
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| @llvm/pr-subscribers-tools-llvm-exegesis Author: Tulio Magno Quites Machado Filho (tuliom) ChangesThis reverts commit 475531b. But it does not revert the changes from commits Full diff: https://github.com/llvm/llvm-project/pull/142382.diff 2 Files Affected:
diff --git a/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s b/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s deleted file mode 100644 index 72009756ed1d5..0000000000000 --- a/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s +++ /dev/null @@ -1,14 +0,0 @@ -llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s - -# TODO: This is failing on some systems that have hardware support for -# pointer authentication. This needs to be fixed before reenabling. -# REQUIRES: disabled - -# REQUIRES: aarch64-registered-target - -# Check for skipping of illegal instruction errors (AUT and LDGM) -# RUN: llvm-exegesis -mcpu=neoverse-v2 -mode=latency --opcode-name=AUTIA --benchmark-phase=assemble-measured-code 2>&1 | FileCheck %s --check-prefix=CHECK-AUTIA -# CHECK-AUTIA-NOT: snippet crashed while running: Illegal instruction - -# RUN: llvm-exegesis -mcpu=neoverse-v2 -mode=latency --opcode-name=LDGM --benchmark-phase=assemble-measured-code 2>&1 | FileCheck %s --check-prefix=CHECK-LDGM -# CHECK-LDGM: LDGM: Unsupported opcode: load tag multiple diff --git a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp index a1eb5a46f21fc..d6f4c5220f71d 100644 --- a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp +++ b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp @@ -12,12 +12,6 @@ #if defined(__aarch64__) && defined(__linux__) #include <linux/prctl.h> // For PR_PAC_* constants #include <sys/prctl.h> -#ifndef PR_PAC_SET_ENABLED_KEYS -#define PR_PAC_SET_ENABLED_KEYS 60 -#endif -#ifndef PR_PAC_GET_ENABLED_KEYS -#define PR_PAC_GET_ENABLED_KEYS 61 -#endif #ifndef PR_PAC_APIAKEY #define PR_PAC_APIAKEY (1UL << 0) #endif @@ -38,47 +32,6 @@ namespace llvm { namespace exegesis { -bool isPointerAuth(unsigned Opcode) { - switch (Opcode) { - default: - return false; - - // FIXME: Pointer Authentication instructions. - // We would like to measure these instructions, but they can behave - // differently on different platforms, and maybe the snippets need to look - // different for these instructions, - // Platform-specific handling: On Linux, we disable authentication, may - // interfere with measurements. On non-Linux platforms, disable opcodes for - // now. - case AArch64::AUTDA: - case AArch64::AUTDB: - case AArch64::AUTDZA: - case AArch64::AUTDZB: - case AArch64::AUTIA: - case AArch64::AUTIA1716: - case AArch64::AUTIASP: - case AArch64::AUTIAZ: - case AArch64::AUTIB: - case AArch64::AUTIB1716: - case AArch64::AUTIBSP: - case AArch64::AUTIBZ: - case AArch64::AUTIZA: - case AArch64::AUTIZB: - return true; - } -} - -bool isLoadTagMultiple(unsigned Opcode) { - switch (Opcode) { - default: - return false; - - // Load tag multiple instruction - case AArch64::LDGM: - return true; - } -} - static unsigned getLoadImmediateOpcode(unsigned RegBitWidth) { switch (RegBitWidth) { case 32: @@ -198,35 +151,6 @@ class ExegesisAArch64Target : public ExegesisTarget { // Function return is a pseudo-instruction that needs to be expanded PM.add(createAArch64ExpandPseudoPass()); } - - const char *getIgnoredOpcodeReasonOrNull(const LLVMState &State, - unsigned Opcode) const override { - if (const char *Reason = - ExegesisTarget::getIgnoredOpcodeReasonOrNull(State, Opcode)) - return Reason; - - if (isPointerAuth(Opcode)) { -#if defined(__aarch64__) && defined(__linux__) - // Disable all PAC keys. Note that while we expect the measurements to - // be the same with PAC keys disabled, they could potentially be lower - // since authentication checks are bypassed. - if (prctl(PR_PAC_SET_ENABLED_KEYS, - PR_PAC_APIAKEY | PR_PAC_APIBKEY | PR_PAC_APDAKEY | - PR_PAC_APDBKEY, // all keys - 0, // disable all - 0, 0) < 0) { - return "Failed to disable PAC keys"; - } -#else - return "Unsupported opcode: isPointerAuth"; -#endif - } - - if (isLoadTagMultiple(Opcode)) - return "Unsupported opcode: load tag multiple"; - - return nullptr; - } }; } // namespace |
Contributor Author
| Copying some folks from PR #136868 : This commit is still causing issues in |
Contributor
| Hi @tuliom , is the opcode test also crashing with the commit ? |
abhilash1910 reviewed Jun 2, 2025
| #include "AArch64RegisterInfo.h" | ||
| | ||
| #if defined(__aarch64__) && defined(__linux__) | ||
| #include <linux/prctl.h> // For PR_PAC_* constants |
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@abhilash1910 I believe that would require to also revert 36850a0 and 5dc3cd0 because they depend on this header.
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I think this header is duplicated in sys/prctl.h ; but sure we can keep it and remove safely in my PR. Thanks
Contributor Author
Yes, it is. However it doesn't give too much information. |
tstellar approved these changes Jun 2, 2025
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I'm in favor of reverting this. The test has been failing for over a month, and I think it's better to revert while the fix is still being worked on.
lakshayk-nv added a commit to lakshayk-nv/llvm-project that referenced this pull request Jun 3, 2025
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This reverts commit 475531b. But it does not revert the changes from commits
36850a0 and
5dc3cd0.