RISCVAsmBackend::shouldInsertExtraNopBytesForCodeAlign() assumed that the
align specified would be greater than or equal to the minimum nop length, but
that is not always the case - for example if a user specifies ".align 0" in
assembly.
Differential Revision: https://reviews.llvm.org/D63274
Patch by Edward Jones.
llvm-svn: 366176
bool HasStdExtC = STI.getFeatureBits()[RISCV::FeatureStdExtC];
unsigned MinNopLen = HasStdExtC ? 2 : 4;
- Size = AF.getAlignment() - MinNopLen;
- return true;
+ if (AF.getAlignment() <= MinNopLen) {
+ return false;
+ } else {
+ Size = AF.getAlignment() - MinNopLen;
+ return true;
+ }
}
// We need to insert R_RISCV_ALIGN relocation type to indicate the
ret
# NORELAX-RELOC-NOT: R_RISCV
# C-EXT-NORELAX-RELOC-NOT: R_RISCV
+# Code alignment of a byte size less than the size of a nop must be treated
+# as no alignment. This used to trigger a fatal error with relaxation enabled
+# as the calculation to emit the worst-case sequence of nops would overflow.
+ .p2align 1
+ add a0, a0, a1
+ .p2align 0
+ add a0, a0, a1
# We only need to insert R_RISCV_ALIGN for code section
# when the linker relaxation enabled.
.data