[llvm] [LangRef] Document the fourth operand for vp.cttz/ctlz. NFC (PR #97387)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/97387

None

>From 855d92e91e1e3728b1482d08471708ac14685956 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Mon, 1 Jul 2024 23:08:56 -0700
Subject: [PATCH] [LangRef] Document the fourth operand for vp.cttz/ctlz. NFC

---
 llvm/docs/LangRef.rst | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index e2c47204e628f..ed988e48daa09 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -24503,7 +24503,9 @@ Arguments:
 The first operand and the result have the same vector of integer type. The
 second operand is the vector mask and has the same number of elements as the
 result vector type. The third operand is the explicit vector length of the
-operation.
+operation. The fourth operand is a constant flag that indicates whether the
+intrinsic returns a valid result if the first operand is zero. If the first
+operand is zero and the fourth operand is true, the result is poison.
 
 Semantics:
 """"""""""
@@ -24550,7 +24552,9 @@ Arguments:
 The first operand and the result have the same vector of integer type. The
 second operand is the vector mask and has the same number of elements as the
 result vector type. The third operand is the explicit vector length of the
-operation.
+operation. The fourth operand is a constant flag that indicates whether the
+intrinsic returns a valid result if the first operand is zero. If the first
+operand is zero and the fourth operand is true, the result is poison.
 
 Semantics:
 """"""""""