[ConstraintElim] Add comments. NFC.

dtcxzyw · dtcxzyw · commit 7bbf80170618 · 2025-11-24T23:42:10.000+08:00
diff --git a/llvm/test/Transforms/ConstraintElimination/shr-exact.ll b/llvm/test/Transforms/ConstraintElimination/shr-exact.ll
@@ -153,7 +153,8 @@ entry:
   ret i1 %cmp
 }
 
-
+; LShr doesn't preserve the sign of the value, so we cannot perform
+; the transformation for signed comparisons.
 define i1 @precond_icmp_lshr_and_lshr_signed_pred(i64 %x, i64 %y) {
 ; CHECK-LABEL: define i1 @precond_icmp_lshr_and_lshr_signed_pred(
 ; CHECK-SAME: i64 [[X:%.*]], i64 [[Y:%.*]]) {

Original file line number	Diff line number	Diff line change
`@@ -153,7 +153,8 @@ entry:`
`153`	`153`	`ret i1 %cmp`
`154`	`154`	`}`
`155`	`155`
`156`		`-`
	`156`	`+; LShr doesn't preserve the sign of the value, so we cannot perform`
	`157`	`+; the transformation for signed comparisons.`
`157`	`158`	`define i1 @precond_icmp_lshr_and_lshr_signed_pred(i64 %x, i64 %y) {`
`158`	`159`	`; CHECK-LABEL: define i1 @precond_icmp_lshr_and_lshr_signed_pred(`
`159`	`160`	`; CHECK-SAME: i64 [[X:%.]], i64 [[Y:%.]]) {`