https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/164354
Backport f3a60cf8dd602958f706c11db66e401257364be7 Requested by: @androm3da >From 9649dbef3d692639cea0abac0cdc820aac990e34 Mon Sep 17 00:00:00 2001 From: Alexey Karyakin <[email protected]> Date: Mon, 20 Oct 2025 19:42:16 -0500 Subject: [PATCH] [Hexagon] Incorrect MIR after "hexinsert" pass (#164021) The "hexinsert" pass tries to replace bitfield operations with Hexagon `insert` instructions. To limit memory usage, there is a limit on the internal table size. When the limit is reached, the state is not correctly cleaned up so defs from from new `insert` instructions are not deleted after processing the basic block. Later, these defs can be incorrectly used in other basic blocks even they are not reachable. Then compiler will crash with: *** Bad machine code: Virtual register defs don't dominate all uses. *** Fixes: #163774 (cherry picked from commit f3a60cf8dd602958f706c11db66e401257364be7) --- llvm/lib/Target/Hexagon/HexagonGenInsert.cpp | 8 +++- llvm/test/CodeGen/Hexagon/insert-big.ll | 45 ++++++++++++++++++++ 2 files changed, 51 insertions(+), 2 deletions(-) create mode 100644 llvm/test/CodeGen/Hexagon/insert-big.ll diff --git a/llvm/lib/Target/Hexagon/HexagonGenInsert.cpp b/llvm/lib/Target/Hexagon/HexagonGenInsert.cpp index a9201460d8e2e..2399e2a28eb22 100644 --- a/llvm/lib/Target/Hexagon/HexagonGenInsert.cpp +++ b/llvm/lib/Target/Hexagon/HexagonGenInsert.cpp @@ -921,6 +921,10 @@ void HexagonGenInsert::collectInBlock(MachineBasicBlock *B, // successors have been processed. RegisterSet BlockDefs, InsDefs; for (MachineInstr &MI : *B) { + // Stop if the map size is too large. + if (IFMap.size() >= MaxIFMSize) + break; + InsDefs.clear(); getInstrDefs(&MI, InsDefs); // Leave those alone. They are more transparent than "insert". @@ -943,8 +947,8 @@ void HexagonGenInsert::collectInBlock(MachineBasicBlock *B, findRecordInsertForms(VR, AVs); // Stop if the map size is too large. - if (IFMap.size() > MaxIFMSize) - return; + if (IFMap.size() >= MaxIFMSize) + break; } } diff --git a/llvm/test/CodeGen/Hexagon/insert-big.ll b/llvm/test/CodeGen/Hexagon/insert-big.ll new file mode 100644 index 0000000000000..a298930b6da6d --- /dev/null +++ b/llvm/test/CodeGen/Hexagon/insert-big.ll @@ -0,0 +1,45 @@ +; Check that llc does not abort, which happened due to incorrect MIR. +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=1 < %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=2 < %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=3 < %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=4 < %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=5 < %s + +; Look for this symptom, in case llc does not check invalid IR. +; CHECK-NOT: insert(%14,%5,#5,#5) + +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=1 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=2 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=3 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=4 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s +; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=5 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s + +define i32 @f(i32 %0, i32 %1, i32 %2) { +entry: + switch i32 %0, label %common.ret1 [ + i32 8907, label %3 + i32 4115, label %6 + ] + +common.ret1: + %common.ret1.op = phi i32 [ %5, %3 ], [ %526, %6 ], [ 0, %entry ] + ret i32 %common.ret1.op + +3: + %4 = shl i32 %2, 5 + %5 = and i32 %4, 992 + br label %common.ret1 + +6: + %7 = shl i32 %0, 10 + %8 = and i32 %7, 7168 + %9 = shl i32 %0, 5 + %10 = and i32 %9, 992 + %11 = or i32 %10, %8 + %12 = and i32 %0, 1 + %13 = or i32 %11, %12 + %14 = shl i32 %1, 1 + %15 = and i32 %14, 2031616 + %526 = or i32 %13, %15 + br label %common.ret1 +} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
