[X86] Add comments to clarify some non-obvious lines in the stackmap-nops.ll

[oota-llvm.git] / test / MC / X86 / stackmap-nops.ll

diff --git a/test/MC/X86/stackmap-nops.ll b/test/MC/X86/stackmap-nops.ll
index 2b0b88c80fab80fea02afa2d4e74f381ee500714..a0d441866035c92de52bd0f91c1aa892808c1f74 100644 (file)
--- a/test/MC/X86/stackmap-nops.ll
+++ b/test/MC/X86/stackmap-nops.ll
@@ -41,6 +41,9 @@ entry:
   tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 13, i32 13)
   tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 14, i32 14)
   tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 15, i32 15)
+; Add an extra stackmap with a zero-length shadow to thwart the shadow
+; optimization. This will force all 15 bytes of the previous shadow to be
+; padded with nops.
   tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 16, i32 0)
   ret void
 }