[Mlir-commits] [mlir] [mlir][EmitC] Fix evaluation order of expressions (PR #93549)
Simon Camphausen
llvmlistbot at llvm.org
Tue May 28 23:43:52 PDT 2024
https://github.com/simon-camp updated https://github.com/llvm/llvm-project/pull/93549
>From 9c5f7974b61b19cd5fe4bb7de6fc184e636a7b0e Mon Sep 17 00:00:00 2001
From: Simon Camphausen <simon.camphausen at iml.fraunhofer.de>
Date: Tue, 28 May 2024 13:36:11 +0000
Subject: [PATCH 1/4] [mlir][EmitC] Fix evaluation order of expressions
Expressions with the same precedence were not paranthesized and therefore were possibly evaluated in the wrong order depending on the shape of the expression tree.
---
mlir/lib/Target/Cpp/TranslateToCpp.cpp | 6 +++++-
mlir/test/Target/Cpp/expressions.mlir | 17 +++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/mlir/lib/Target/Cpp/TranslateToCpp.cpp b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
index 7db7163bac4ab..3e7cd30853a98 100644
--- a/mlir/lib/Target/Cpp/TranslateToCpp.cpp
+++ b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
@@ -1316,7 +1316,11 @@ LogicalResult CppEmitter::emitOperand(Value value) {
FailureOr<int> precedence = getOperatorPrecedence(def);
if (failed(precedence))
return failure();
- bool encloseInParenthesis = precedence.value() < getExpressionPrecedence();
+
+ // Expressions with the same precedence need to be paranthesized, as
+ // they might be evaluated in the wrong order depending on the shape of the
+ // expression tree.
+ bool encloseInParenthesis = precedence.value() <= getExpressionPrecedence();
if (encloseInParenthesis) {
os << "(";
pushExpressionPrecedence(lowestPrecedence());
diff --git a/mlir/test/Target/Cpp/expressions.mlir b/mlir/test/Target/Cpp/expressions.mlir
index 2eda58902cb1d..8a3bac3233a93 100644
--- a/mlir/test/Target/Cpp/expressions.mlir
+++ b/mlir/test/Target/Cpp/expressions.mlir
@@ -83,6 +83,23 @@ func.func @paranthesis_for_low_precedence(%arg0: i32, %arg1: i32, %arg2: i32) ->
return %e : f32
}
+// CPP-DEFAULT: int32_t paranthesis_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
+// CPP-DEFAULT-NEXT: return [[VAL_3]] / ([[VAL_1]] * [[VAL_2]]);
+// CPP-DEFAULT-NEXT: }
+
+// CPP-DECLTOP: int32_t paranthesis_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
+// CPP-DECLTOP-NEXT: return [[VAL_3]] / ([[VAL_1]] * [[VAL_2]]);
+// CPP-DECLTOP-NEXT: }
+func.func @paranthesis_for_same_precedence(%arg0: i32, %arg1: i32, %arg2: i32) -> i32 {
+ %e = emitc.expression : i32 {
+ %0 = emitc.mul %arg0, %arg1 : (i32, i32) -> i32
+ %1 = emitc.div %arg2, %0 : (i32, i32) -> i32
+ emitc.yield %1 : i32
+ }
+
+ return %e : i32
+}
+
// CPP-DEFAULT: int32_t multiple_uses(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]], int32_t [[VAL_4:v[0-9]+]]) {
// CPP-DEFAULT-NEXT: bool [[VAL_5:v[0-9]+]] = bar([[VAL_1]] * [[VAL_2]], [[VAL_3]]) - [[VAL_4]] < [[VAL_2]];
// CPP-DEFAULT-NEXT: int32_t [[VAL_6:v[0-9]+]];
>From d87cfd58dc8b47da6a633031832b5c9b818bdb8d Mon Sep 17 00:00:00 2001
From: Simon Camphausen <simon.camphausen at iml.fraunhofer.de>
Date: Wed, 29 May 2024 06:39:11 +0000
Subject: [PATCH 2/4] Review comment
---
mlir/lib/Target/Cpp/TranslateToCpp.cpp | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mlir/lib/Target/Cpp/TranslateToCpp.cpp b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
index 3e7cd30853a98..221603c71ba59 100644
--- a/mlir/lib/Target/Cpp/TranslateToCpp.cpp
+++ b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
@@ -1317,9 +1317,9 @@ LogicalResult CppEmitter::emitOperand(Value value) {
if (failed(precedence))
return failure();
- // Expressions with the same precedence need to be paranthesized, as
- // they might be evaluated in the wrong order depending on the shape of the
- // expression tree.
+ // Sub-expressions with equal or lower precedence need to be paranthesized,
+ // as they might be evaluated in the wrong order depending on the shape of
+ // the expression tree.
bool encloseInParenthesis = precedence.value() <= getExpressionPrecedence();
if (encloseInParenthesis) {
os << "(";
>From 59cd662e0c9d2a8c53b6e5b7b38cc513120e2051 Mon Sep 17 00:00:00 2001
From: Simon Camphausen <simon.camphausen at iml.fraunhofer.de>
Date: Wed, 29 May 2024 08:42:52 +0200
Subject: [PATCH 3/4] Apply suggestions from code review
Rename tests
Co-authored-by: Matthias Gehre <matthias.gehre at amd.com>
---
mlir/test/Target/Cpp/expressions.mlir | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mlir/test/Target/Cpp/expressions.mlir b/mlir/test/Target/Cpp/expressions.mlir
index 8a3bac3233a93..8604ec8ed11f6 100644
--- a/mlir/test/Target/Cpp/expressions.mlir
+++ b/mlir/test/Target/Cpp/expressions.mlir
@@ -83,11 +83,11 @@ func.func @paranthesis_for_low_precedence(%arg0: i32, %arg1: i32, %arg2: i32) ->
return %e : f32
}
-// CPP-DEFAULT: int32_t paranthesis_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
+// CPP-DEFAULT: int32_t parentheses_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
// CPP-DEFAULT-NEXT: return [[VAL_3]] / ([[VAL_1]] * [[VAL_2]]);
// CPP-DEFAULT-NEXT: }
-// CPP-DECLTOP: int32_t paranthesis_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
+// CPP-DECLTOP: int32_t parentheses_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
// CPP-DECLTOP-NEXT: return [[VAL_3]] / ([[VAL_1]] * [[VAL_2]]);
// CPP-DECLTOP-NEXT: }
func.func @paranthesis_for_same_precedence(%arg0: i32, %arg1: i32, %arg2: i32) -> i32 {
>From 7764f4117674cb82ad1a72648cbe3ed8f2f888d0 Mon Sep 17 00:00:00 2001
From: Simon Camphausen <simon.camphausen at iml.fraunhofer.de>
Date: Wed, 29 May 2024 08:43:44 +0200
Subject: [PATCH 4/4] Update mlir/test/Target/Cpp/expressions.mlir
Co-authored-by: Matthias Gehre <matthias.gehre at amd.com>
---
mlir/test/Target/Cpp/expressions.mlir | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mlir/test/Target/Cpp/expressions.mlir b/mlir/test/Target/Cpp/expressions.mlir
index 8604ec8ed11f6..ad534d058e1a2 100644
--- a/mlir/test/Target/Cpp/expressions.mlir
+++ b/mlir/test/Target/Cpp/expressions.mlir
@@ -90,7 +90,7 @@ func.func @paranthesis_for_low_precedence(%arg0: i32, %arg1: i32, %arg2: i32) ->
// CPP-DECLTOP: int32_t parentheses_for_same_precedence(int32_t [[VAL_1:v[0-9]+]], int32_t [[VAL_2:v[0-9]+]], int32_t [[VAL_3:v[0-9]+]]) {
// CPP-DECLTOP-NEXT: return [[VAL_3]] / ([[VAL_1]] * [[VAL_2]]);
// CPP-DECLTOP-NEXT: }
-func.func @paranthesis_for_same_precedence(%arg0: i32, %arg1: i32, %arg2: i32) -> i32 {
+func.func @parentheses_for_same_precedence(%arg0: i32, %arg1: i32, %arg2: i32) -> i32 {
%e = emitc.expression : i32 {
%0 = emitc.mul %arg0, %arg1 : (i32, i32) -> i32
%1 = emitc.div %arg2, %0 : (i32, i32) -> i32
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