[InferAttrs] Add nocapture/writeonly to string/mem libcalls

One step closer to fix PR47644.

Differential Revision: https://reviews.llvm.org/D89645

diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index bf63d7b..800db17 100644 (file)
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -35,6 +35,7 @@ STATISTIC(NumReadOnly, "Number of functions inferred as readonly");
 STATISTIC(NumArgMemOnly, "Number of functions inferred as argmemonly");
 STATISTIC(NumNoUnwind, "Number of functions inferred as nounwind");
 STATISTIC(NumNoCapture, "Number of arguments inferred as nocapture");
+STATISTIC(NumWriteOnlyArg, "Number of arguments inferred as writeonly");
 STATISTIC(NumReadOnlyArg, "Number of arguments inferred as readonly");
 STATISTIC(NumNoAlias, "Number of function returns inferred as noalias");
 STATISTIC(NumNoUndef, "Number of function returns inferred as noundef returns");
@@ -105,6 +106,15 @@ static bool setOnlyReadsMemory(Function &F, unsigned ArgNo) {
   return true;
 }
 
+static bool setOnlyWritesMemory(Function &F, unsigned ArgNo) {
+  if (F.hasParamAttribute(ArgNo, Attribute::WriteOnly))
+    return false;
+  F.addParamAttr(ArgNo, Attribute::WriteOnly);
+  ++NumWriteOnlyArg;
+  return true;
+}
+
+
 static bool setRetNoUndef(Function &F) {
   if (!F.getReturnType()->isVoidTy() &&
       !F.hasAttribute(AttributeList::ReturnIndex, Attribute::NoUndef)) {
@@ -220,6 +230,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setOnlyReadsMemory(F, 1);
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setDoesNotAlias(F, 1);
@@ -303,6 +314,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setDoesNotAlias(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
@@ -311,6 +323,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setDoesNotAlias(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotCapture(F, 2);
     Changed |= setOnlyReadsMemory(F, 2);
     return Changed;
@@ -356,6 +369,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setReturnedArg(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
@@ -364,6 +378,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setReturnedArg(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
@@ -372,6 +387,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotAlias(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
@@ -450,8 +466,9 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotCapture(F, 0);
-    Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 0);
+    Changed |= setOnlyWritesMemory(F, 1);
+    Changed |= setDoesNotCapture(F, 1);
     return Changed;
   case LibFunc_bcmp:
     Changed |= setDoesNotThrow(F);
@@ -464,6 +481,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotCapture(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     return Changed;
   case LibFunc_calloc:
     Changed |= setRetNoUndef(F);
@@ -922,6 +940,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
   case LibFunc_memset_pattern16:
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotCapture(F, 0);
+    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;

diff --git a/llvm/test/Analysis/BasicAA/libfuncs.ll b/llvm/test/Analysis/BasicAA/libfuncs.ll
index 78d1b28..7996389 100644 (file)
--- a/llvm/test/Analysis/BasicAA/libfuncs.ll
+++ b/llvm/test/Analysis/BasicAA/libfuncs.ll
@@ -106,13 +106,14 @@ entry:
 declare i8* @memccpy(i8*, i8*, i32, i64)
 
 ; CHECK-LABEL: Function: test_memccpy_const_size
-; CHECK:      Both ModRef:  Ptr: i8* %a     <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
+; CHECK:      Just Mod:  Ptr: i8* %a        <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
 ; CHECK-NEXT: Just Ref:  Ptr: i8* %b        <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
-; CHECK-NEXT: Both ModRef:  Ptr: i8* %res   <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
-; CHECK-NEXT: Both ModRef:  Ptr: i8* %a.gep.1       <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
+; CHECK-NEXT: Just Mod:  Ptr: i8* %res      <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
+; CHECK-NEXT: Just Mod:  Ptr: i8* %a.gep.1  <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
 ; CHECK-NEXT: NoModRef:  Ptr: i8* %a.gep.5  <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
 ; CHECK-NEXT: Just Ref:  Ptr: i8* %b.gep.1  <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
 ; CHECK-NEXT: NoModRef:  Ptr: i8* %b.gep.5  <->  %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)
+
 define i8* @test_memccpy_const_size(i8* noalias %a, i8* noalias %b) {
 entry:
   %res = call i8* @memccpy(i8* %a, i8* %b, i32 42, i64 4)

diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index a003eef..908ced9 100644 (file)
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -247,10 +247,10 @@ declare i64 @atoll(i8*)
 ; CHECK-NVPTX-NOT: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
 declare i32 @bcmp(i8*, i8*, i64)
 
-; CHECK: declare void @bcopy(i8* nocapture readonly, i8* nocapture, i64)  [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
+; CHECK: declare void @bcopy(i8* nocapture readonly, i8* nocapture writeonly, i64)  [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
 declare void @bcopy(i8*, i8*, i64)
 
-; CHECK: declare void @bzero(i8* nocapture, i64)  [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
+; CHECK: declare void @bzero(i8* nocapture writeonly, i64)  [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
 declare void @bzero(i8*, i64)
 
 ; CHECK: declare noalias noundef i8* @calloc(i64, i64) [[G1]]
@@ -619,7 +619,7 @@ declare i8* @malloc(i64)
 ; CHECK-LINUX: declare noalias i8* @memalign(i64, i64) [[G0]]
 declare i8* @memalign(i64, i64)
 
-; CHECK: declare i8* @memccpy(i8* noalias, i8* noalias nocapture readonly, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
+; CHECK: declare i8* @memccpy(i8* noalias writeonly, i8* noalias nocapture readonly, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
 declare i8* @memccpy(i8*, i8*, i32, i64)
 
 ; CHECK-LINUX:   declare i8* @memchr(i8*, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
@@ -630,13 +630,13 @@ declare i8* @memchr(i8*, i32, i64)
 ; CHECK: declare i32 @memcmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @memcmp(i8*, i8*, i64)
 
-; CHECK: declare i8* @memcpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @memcpy(i8* noalias returned writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @memcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @mempcpy(i8* noalias, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @mempcpy(i8* noalias writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @mempcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @memmove(i8* returned, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @memmove(i8* returned writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @memmove(i8*, i8*, i64)
 
 ; CHECK: declare i8* @memset(i8*, i32, i64) [[G0]]
@@ -795,10 +795,10 @@ declare x86_fp80 @sinhl(x86_fp80)
 ; CHECK: declare x86_fp80 @sinl(x86_fp80) [[G0]]
 declare x86_fp80 @sinl(x86_fp80)
 
-; CHECK: declare noundef i32 @snprintf(i8* noalias nocapture noundef, i64 noundef, i8* nocapture noundef readonly, ...) [[G1]]
+; CHECK: declare noundef i32 @snprintf(i8* noalias nocapture noundef writeonly, i64 noundef, i8* nocapture noundef readonly, ...) [[G1]]
 declare i32 @snprintf(i8*, i64, i8*, ...)
 
-; CHECK: declare noundef i32 @sprintf(i8* noalias nocapture noundef, i8* nocapture noundef readonly, ...) [[G1]]
+; CHECK: declare noundef i32 @sprintf(i8* noalias nocapture noundef writeonly, i8* nocapture noundef readonly, ...) [[G1]]
 declare i32 @sprintf(i8*, i8*, ...)
 
 ; CHECK: declare double @sqrt(double) [[G0]]
@@ -825,16 +825,16 @@ declare i32 @statvfs(i8*, %opaque*)
 ; CHECK-LINUX: declare noundef i32 @statvfs64(i8* nocapture noundef readonly, %opaque* nocapture noundef) [[G1]]
 declare i32 @statvfs64(i8*, %opaque*)
 
-; CHECK: declare i8* @stpcpy(i8* noalias, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @stpcpy(i8* noalias writeonly, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @stpcpy(i8*, i8*)
 
-; CHECK: declare i8* @stpncpy(i8* noalias, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @stpncpy(i8* noalias writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @stpncpy(i8*, i8*, i64)
 
 ; CHECK: declare i32 @strcasecmp(i8* nocapture, i8* nocapture) [[G2]]
 declare i32 @strcasecmp(i8*, i8*)
 
-; CHECK: declare i8* @strcat(i8* noalias returned, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @strcat(i8* noalias returned writeonly, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @strcat(i8*, i8*)
 
 ; CHECK: declare i8* @strchr(i8*, i32) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
@@ -846,7 +846,7 @@ declare i32 @strcmp(i8*, i8*)
 ; CHECK: declare i32 @strcoll(i8* nocapture, i8* nocapture) [[G2]]
 declare i32 @strcoll(i8*, i8*)
 
-; CHECK: declare i8* @strcpy(i8* noalias returned, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @strcpy(i8* noalias returned writeonly, i8* noalias nocapture readonly) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @strcpy(i8*, i8*)
 
 ; CHECK: declare i64 @strcspn(i8* nocapture, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
@@ -861,13 +861,13 @@ declare i64 @strlen(i8*)
 ; CHECK: declare i32 @strncasecmp(i8* nocapture, i8* nocapture, i64) [[G2]]
 declare i32 @strncasecmp(i8*, i8*, i64)
 
-; CHECK: declare i8* @strncat(i8* noalias returned, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @strncat(i8* noalias returned writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @strncat(i8*, i8*, i64)
 
 ; CHECK: declare i32 @strncmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @strncmp(i8*, i8*, i64)
 
-; CHECK: declare i8* @strncpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
+; CHECK: declare i8* @strncpy(i8* noalias returned writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @strncpy(i8*, i8*, i64)
 
 ; CHECK: declare noalias i8* @strndup(i8* nocapture readonly, i64) [[G1]]
@@ -1007,7 +1007,7 @@ declare i64 @write(i32, i8*, i64)
 
 
 ; memset_pattern16 isn't available everywhere.
-; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE:#[0-9]+]]
+; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE:#[0-9]+]]
 declare void @memset_pattern16(i8*, i8*, i64)
 
 ; CHECK: attributes [[G0]] = { nofree }

diff --git a/llvm/test/Transforms/LoopIdiom/basic.ll b/llvm/test/Transforms/LoopIdiom/basic.ll
index 60c5521..625de6e 100644 (file)
--- a/llvm/test/Transforms/LoopIdiom/basic.ll
+++ b/llvm/test/Transforms/LoopIdiom/basic.ll
@@ -1064,5 +1064,5 @@ exit:
 }
 
 ; Validate that "memset_pattern" has the proper attributes.
-; CHECK: declare void @memset_pattern16(i8* nocapture, i8* nocapture readonly, i64) [[ATTRS:#[0-9]+]]
+; CHECK: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ATTRS:#[0-9]+]]
 ; CHECK: [[ATTRS]] = { argmemonly nofree }