[clang] [clang codegen] Emit int TBAA metadata on more FP math libcalls (PR #100302)

via cfe-commits cfe-commits at lists.llvm.org
Sat Jul 27 00:59:54 PDT 2024


https://github.com/vfdff updated https://github.com/llvm/llvm-project/pull/100302

>From c750234674531788ee26958954a5f9a6b59ea866 Mon Sep 17 00:00:00 2001
From: zhongyunde 00443407 <zhongyunde at huawei.com>
Date: Tue, 23 Jul 2024 23:10:42 -0400
Subject: [PATCH 1/3] [clang codegen] Emit int TBAA metadata on more FP math
 libcalls

Follow PR96025, except expf, more FP math libcalls in libm
should also be supported.

Fix https://github.com/llvm/llvm-project/issues/86635
---
 clang/lib/CodeGen/CGBuiltin.cpp | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index a0d03b87ccdc9..a9696ebe61e3a 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -692,23 +692,22 @@ static RValue emitLibraryCall(CodeGenFunction &CGF, const FunctionDecl *FD,
   RValue Call =
       CGF.EmitCall(E->getCallee()->getType(), callee, E, ReturnValueSlot());
 
-  // Check the supported intrinsic.
+  ASTContext &Context = CGF.getContext();
   if (unsigned BuiltinID = FD->getBuiltinID()) {
     auto IsErrnoIntrinsic = [&]() -> unsigned {
-      switch (BuiltinID) {
-      case Builtin::BIexpf:
-      case Builtin::BI__builtin_expf:
-      case Builtin::BI__builtin_expf128:
+      // Check whether a FP math builtin function, such as BI__builtin_expf
+      QualType ResultTy = FD->getReturnType();
+      bool IsMathLibCall =
+          Context.BuiltinInfo.isLibFunction(BuiltinID) ||
+          Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID);
+      if (IsMathLibCall && CGF.ConvertType(ResultTy)->isFloatingPointTy())
         return true;
-      }
-      // TODO: support more FP math libcalls
       return false;
     }();
 
     // Restrict to target with errno, for example, MacOS doesn't set errno.
     if (IsErrnoIntrinsic && CGF.CGM.getLangOpts().MathErrno &&
         !CGF.Builder.getIsFPConstrained()) {
-      ASTContext &Context = CGF.getContext();
       // Emit "int" TBAA metadata on FP math libcalls.
       clang::QualType IntTy = Context.IntTy;
       TBAAAccessInfo TBAAInfo = CGF.CGM.getTBAAAccessInfo(IntTy);

>From fb81f300280582b2e820e32094dee9e6ed1da75f Mon Sep 17 00:00:00 2001
From: zhongyunde 00443407 <zhongyunde at huawei.com>
Date: Wed, 24 Jul 2024 03:38:42 -0400
Subject: [PATCH 2/3] Add a new test calls fabs

---
 clang/test/CodeGen/math-libcalls-tbaa.cpp | 29 +++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/clang/test/CodeGen/math-libcalls-tbaa.cpp b/clang/test/CodeGen/math-libcalls-tbaa.cpp
index f15938dee0272..2812e82abe652 100644
--- a/clang/test/CodeGen/math-libcalls-tbaa.cpp
+++ b/clang/test/CodeGen/math-libcalls-tbaa.cpp
@@ -4,23 +4,40 @@
 // RUN:  %clang_cc1 -triple=aarch64-unknown-linux-gnu -fmath-errno -O3 -new-struct-path-tbaa -emit-llvm -o - -x c++ %s | FileCheck %s -check-prefixes=CHECK,NewStructPathTBAA
 
 extern "C" float expf(float);
+extern "C" double fabs(double);
 
 // Emit int TBAA metadata on FP math libcalls, which is useful for alias analysis
 
 // CHECK-LABEL: define dso_local float @foo(
-// CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]], float noundef [[R2INV:%.*]], i32 noundef [[N:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
 // CHECK-NEXT:  [[ENTRY:.*:]]
 // CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[NUM]], i64 40
 // CHECK-NEXT:    [[TMP0:%.*]] = load float, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2:![0-9]+]]
-// CHECK-NEXT:    [[CALL:%.*]] = tail call float @expf(float noundef [[TMP0]]) #[[ATTR2:[0-9]+]], !tbaa [[TBAA6:![0-9]+]]
+// CHECK-NEXT:    [[CALL:%.*]] = tail call float @expf(float noundef [[TMP0]]) #[[ATTR4:[0-9]+]], !tbaa [[TBAA6:![0-9]+]]
 // CHECK-NEXT:    [[MUL:%.*]] = fmul float [[TMP0]], [[CALL]]
 // CHECK-NEXT:    ret float [[MUL]]
 //
-extern "C" float foo (float num[], float r2inv, int n) {
-   const float expm2 =  expf(num[10]);  // Emit TBAA metadata on @expf
+extern "C" float foo (float num[]) {
+   const float expm2 = expf(num[10]);  // Emit TBAA metadata on @expf
    float tmp = expm2 * num[10];
    return tmp;
 }
+
+// CHECK-LABEL: define dso_local double @foo_fabs(
+// CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]]) local_unnamed_addr #[[ATTR2:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[NUM]], i64 80
+// CHECK-NEXT:    [[TMP0:%.*]] = load double, ptr [[ARRAYIDX]], align 8, !tbaa [[TBAA8:![0-9]+]]
+// CHECK-NEXT:    [[TMP1:%.*]] = tail call double @llvm.fabs.f64(double [[TMP0]])
+// CHECK-NEXT:    [[MUL:%.*]] = fmul double [[TMP0]], [[TMP1]]
+// CHECK-NEXT:    ret double [[MUL]]
+//
+extern "C" double foo_fabs (double num[]) {
+   const double expm2 = fabs(num[10]);  // Emit TBAA metadata on @fabs
+   double tmp = expm2 * num[10];
+   return tmp;
+}
+
 //.
 // NoNewStructPathTBAA: [[TBAA2]] = !{[[META3:![0-9]+]], [[META3]], i64 0}
 // NoNewStructPathTBAA: [[META3]] = !{!"float", [[META4:![0-9]+]], i64 0}
@@ -28,6 +45,8 @@ extern "C" float foo (float num[], float r2inv, int n) {
 // NoNewStructPathTBAA: [[META5]] = !{!"Simple C++ TBAA"}
 // NoNewStructPathTBAA: [[TBAA6]] = !{[[META7:![0-9]+]], [[META7]], i64 0}
 // NoNewStructPathTBAA: [[META7]] = !{!"int", [[META4]], i64 0}
+// NoNewStructPathTBAA: [[TBAA8]] = !{[[META9:![0-9]+]], [[META9]], i64 0}
+// NoNewStructPathTBAA: [[META9]] = !{!"double", [[META4]], i64 0}
 //.
 // NewStructPathTBAA: [[TBAA2]] = !{[[META3:![0-9]+]], [[META3]], i64 0, i64 4}
 // NewStructPathTBAA: [[META3]] = !{[[META4:![0-9]+]], i64 4, !"float"}
@@ -35,6 +54,8 @@ extern "C" float foo (float num[], float r2inv, int n) {
 // NewStructPathTBAA: [[META5]] = !{!"Simple C++ TBAA"}
 // NewStructPathTBAA: [[TBAA6]] = !{[[META7:![0-9]+]], [[META7]], i64 0, i64 4}
 // NewStructPathTBAA: [[META7]] = !{[[META4]], i64 4, !"int"}
+// NewStructPathTBAA: [[TBAA8]] = !{[[META9:![0-9]+]], [[META9]], i64 0, i64 8}
+// NewStructPathTBAA: [[META9]] = !{[[META4]], i64 8, !"double"}
 //.
 //// NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
 // NewStructPathTBAA: {{.*}}

>From b4cbc0545a8c96cfcb9e463c3a23828a2158d194 Mon Sep 17 00:00:00 2001
From: zhongyunde 00443407 <zhongyunde at huawei.com>
Date: Thu, 25 Jul 2024 07:42:57 -0400
Subject: [PATCH 3/3] Update with isConstWithoutErrnoAndExceptions

---
 clang/lib/CodeGen/CGBuiltin.cpp           |  8 ++++----
 clang/test/CodeGen/math-libcalls-tbaa.cpp | 20 +++++++++++++++++++-
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index a9696ebe61e3a..addb6e1df4b15 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -697,10 +697,10 @@ static RValue emitLibraryCall(CodeGenFunction &CGF, const FunctionDecl *FD,
     auto IsErrnoIntrinsic = [&]() -> unsigned {
       // Check whether a FP math builtin function, such as BI__builtin_expf
       QualType ResultTy = FD->getReturnType();
-      bool IsMathLibCall =
-          Context.BuiltinInfo.isLibFunction(BuiltinID) ||
-          Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID);
-      if (IsMathLibCall && CGF.ConvertType(ResultTy)->isFloatingPointTy())
+      bool ConstWithoutErrnoAndExceptions =
+          Context.BuiltinInfo.isConstWithoutErrnoAndExceptions(BuiltinID);
+      if (ConstWithoutErrnoAndExceptions &&
+          CGF.ConvertType(ResultTy)->isFloatingPointTy())
         return true;
       return false;
     }();
diff --git a/clang/test/CodeGen/math-libcalls-tbaa.cpp b/clang/test/CodeGen/math-libcalls-tbaa.cpp
index 2812e82abe652..ce1373bde2ead 100644
--- a/clang/test/CodeGen/math-libcalls-tbaa.cpp
+++ b/clang/test/CodeGen/math-libcalls-tbaa.cpp
@@ -4,6 +4,7 @@
 // RUN:  %clang_cc1 -triple=aarch64-unknown-linux-gnu -fmath-errno -O3 -new-struct-path-tbaa -emit-llvm -o - -x c++ %s | FileCheck %s -check-prefixes=CHECK,NewStructPathTBAA
 
 extern "C" float expf(float);
+extern "C" double remainder(double, double);
 extern "C" double fabs(double);
 
 // Emit int TBAA metadata on FP math libcalls, which is useful for alias analysis
@@ -23,6 +24,8 @@ extern "C" float foo (float num[]) {
    return tmp;
 }
 
+//
+// Negative test: fabs cannot set errno
 // CHECK-LABEL: define dso_local double @foo_fabs(
 // CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]]) local_unnamed_addr #[[ATTR2:[0-9]+]] {
 // CHECK-NEXT:  [[ENTRY:.*:]]
@@ -33,7 +36,22 @@ extern "C" float foo (float num[]) {
 // CHECK-NEXT:    ret double [[MUL]]
 //
 extern "C" double foo_fabs (double num[]) {
-   const double expm2 = fabs(num[10]);  // Emit TBAA metadata on @fabs
+   const double expm2 = fabs(num[10]);          // Don't emit TBAA metadata
+   double tmp = expm2 * num[10];
+   return tmp;
+}
+
+// CHECK-LABEL: define dso_local double @foo_remainder(
+// CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]], double noundef [[A:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[NUM]], i64 80
+// CHECK-NEXT:    [[TMP0:%.*]] = load double, ptr [[ARRAYIDX]], align 8, !tbaa [[TBAA8]]
+// CHECK-NEXT:    [[CALL:%.*]] = tail call double @remainder(double noundef [[TMP0]], double noundef [[A]]) #[[ATTR4]], !tbaa [[TBAA6]]
+// CHECK-NEXT:    [[MUL:%.*]] = fmul double [[TMP0]], [[CALL]]
+// CHECK-NEXT:    ret double [[MUL]]
+//
+extern "C" double foo_remainder (double num[], double a) {
+   const double expm2 = remainder(num[10], a);  // Emit TBAA metadata
    double tmp = expm2 * num[10];
    return tmp;
 }



More information about the cfe-commits mailing list