[Mlir-commits] [mlir] [mlir][math] Fix the description of the semantics of math.clampf (PR #175012)

[llvmlistbot at llvm.org]

https://github.com/jack-slingsby updated https://github.com/llvm/llvm-project/pull/175012

>From 51100644e499e96b222d4abc67d7baeb923aa354 Mon Sep 17 00:00:00 2001
From: Jack Slingsby <jack.slingsby at imgtec.com>
Date: Thu, 8 Jan 2026 16:02:40 +0000
Subject: [PATCH 1/2] Fix the description of the semantics of math.clampf

---
 mlir/include/mlir/Dialect/Math/IR/MathOps.td | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mlir/include/mlir/Dialect/Math/IR/MathOps.td b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
index af65af6fedec6..432f08b14a989 100644
--- a/mlir/include/mlir/Dialect/Math/IR/MathOps.td
+++ b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
@@ -365,7 +365,7 @@ def Math_ClampFOp : Math_FloatTernaryOp<"clampf"> {
 
     The semantics of the operation are described by:
     ```
-      clampf(value, min, max) = maxf(minf(value, min), max)
+      clampf(value, min, max) = minf(maxf(value, min), max)
     ```
 
     Example:

>From ba325857d1a1be73c34569860d564835d0692aaa Mon Sep 17 00:00:00 2001
From: Jack Slingsby <jack.slingsby at imgtec.com>
Date: Fri, 16 Jan 2026 15:48:02 +0000
Subject: [PATCH 2/2] Improve description + update the expand ops transform

---
 mlir/include/mlir/Dialect/Math/IR/MathOps.td   | 3 ++-
 mlir/lib/Dialect/Math/Transforms/ExpandOps.cpp | 4 ++--
 mlir/test/Dialect/Math/expand-math.mlir        | 8 ++++----
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/mlir/include/mlir/Dialect/Math/IR/MathOps.td b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
index 432f08b14a989..a7f5e14f74894 100644
--- a/mlir/include/mlir/Dialect/Math/IR/MathOps.td
+++ b/mlir/include/mlir/Dialect/Math/IR/MathOps.td
@@ -365,8 +365,9 @@ def Math_ClampFOp : Math_FloatTernaryOp<"clampf"> {
 
     The semantics of the operation are described by:
     ```
-      clampf(value, min, max) = minf(maxf(value, min), max)
+      clampf(value, min, max) = maxf(minf(value, max), min)
     ```
+    If `min>max` the resulting value is undefined.
 
     Example:
 
diff --git a/mlir/lib/Dialect/Math/Transforms/ExpandOps.cpp b/mlir/lib/Dialect/Math/Transforms/ExpandOps.cpp
index cd68039d0d964..249a95cc7924a 100644
--- a/mlir/lib/Dialect/Math/Transforms/ExpandOps.cpp
+++ b/mlir/lib/Dialect/Math/Transforms/ExpandOps.cpp
@@ -669,8 +669,8 @@ static LogicalResult convertRsqrtOp(math::RsqrtOp op,
 static LogicalResult convertClampfOp(math::ClampFOp op,
                                      PatternRewriter &rewriter) {
   auto minOp = arith::MinimumFOp::create(rewriter, op.getLoc(), op.getValue(),
-                                         op.getMin(), op.getFastmath());
-  rewriter.replaceOpWithNewOp<arith::MaximumFOp>(op, minOp, op.getMax(),
+                                         op.getMax(), op.getFastmath());
+  rewriter.replaceOpWithNewOp<arith::MaximumFOp>(op, minOp, op.getMin(),
                                                  op.getFastmath());
   return success();
 }
diff --git a/mlir/test/Dialect/Math/expand-math.mlir b/mlir/test/Dialect/Math/expand-math.mlir
index 615c607efc3c3..1d26c826e8d6b 100644
--- a/mlir/test/Dialect/Math/expand-math.mlir
+++ b/mlir/test/Dialect/Math/expand-math.mlir
@@ -827,8 +827,8 @@ func.func @unranked_rsqrt_op(%arg: tensor<*xf32>) -> tensor<*xf32>{
 
 // CHECK-LABEL:    func.func @clampf_scalar_op
 // CHECK-SAME:     (%[[ARG:.*]]: f16, %[[MIN:.*]]: f16, %[[MAX:.*]]: f16)
-// CHECK:          %[[V0:.*]] = arith.minimumf %[[ARG]], %[[MIN]] : f16
-// CHECK:          %[[V1:.*]] = arith.maximumf %[[V0]], %[[MAX]] : f16
+// CHECK:          %[[V0:.*]] = arith.minimumf %[[ARG]], %[[MAX]] : f16
+// CHECK:          %[[V1:.*]] = arith.maximumf %[[V0]], %[[MIN]] : f16
 // CHECK:          return %[[V1]] : f16
 
 func.func @clampf_scalar_op(%arg: f16, %min: f16, %max: f16) -> f16 {
@@ -838,8 +838,8 @@ func.func @clampf_scalar_op(%arg: f16, %min: f16, %max: f16) -> f16 {
 
 // CHECK-LABEL:    func.func @clampf_vector_op
 // CHECK-SAME:     (%[[ARG:.*]]: vector<3x4xf32>, %[[MIN:.*]]: vector<3x4xf32>, %[[MAX:.*]]: vector<3x4xf32>)
-// CHECK:          %[[V0:.*]] = arith.minimumf %[[ARG]], %[[MIN]] fastmath<fast> : vector<3x4xf32>
-// CHECK:          %[[V1:.*]] = arith.maximumf %[[V0]], %[[MAX]] fastmath<fast> : vector<3x4xf32>
+// CHECK:          %[[V0:.*]] = arith.minimumf %[[ARG]], %[[MAX]] fastmath<fast> : vector<3x4xf32>
+// CHECK:          %[[V1:.*]] = arith.maximumf %[[V0]], %[[MIN]] fastmath<fast> : vector<3x4xf32>
 // CHECK:          return %[[V1]] : vector<3x4xf32>
 
 func.func @clampf_vector_op(%arg: vector<3x4xf32>, %min: vector<3x4xf32>, %max: vector<3x4xf32>) -> vector<3x4xf32>{