[all-commits] [llvm/llvm-project] 507efb: [MC] Fold A-B when A is a pending label or A/B are...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 507efbcce03d8c2c5dbea3028bc39f02c88fea79
      https://github.com/llvm/llvm-project/commit/507efbcce03d8c2c5dbea3028bc39f02c88fea79
  Author: Fangrui Song <i at maskray.me>
  Date:   2023-06-18 (Sun, 18 Jun 2023)

  Changed paths:
    M llvm/lib/MC/MCExpr.cpp
    M llvm/test/MC/ARM/directive-if-subtraction.s
    M llvm/test/MC/AsmParser/assembler-expressions.s
    M llvm/test/MC/RISCV/cfi-advance.s

  Log Message:
  -----------
  [MC] Fold A-B when A is a pending label or A/B are separated by a MCFillFragment

When the MCAssembler is non-null and the MCAsmLayout is null, we can fold A-B
in these additional cases:

* when A is a pending label (will be reassigned to a real fragment in flushPendingLabels())
* A and B are separated by a MCFillFragment with a constant size