[llvm] da69147 - [InferAttrs] Refine attributes for a few libc routines
Antonio Frighetto via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 13 05:04:09 PDT 2025
Author: Antonio Frighetto
Date: 2025-03-13T12:59:57+01:00
New Revision: da69147a1619813679cef7ee39ec68cf2c8a2732
URL: https://github.com/llvm/llvm-project/commit/da69147a1619813679cef7ee39ec68cf2c8a2732
DIFF: https://github.com/llvm/llvm-project/commit/da69147a1619813679cef7ee39ec68cf2c8a2732.diff
LOG: [InferAttrs] Refine attributes for a few libc routines
Attributes inference has been improved for a few functions.
Particularly, ldexp and variants, as well as abort, may be
marked as `nounwind`, as they do not propagate any exceptions
to the caller, neither they unwind the stack. Besides, fwrite
and fread first argument should be respectively readonly and
writeonly.
Added:
Modified:
llvm/lib/Transforms/Utils/BuildLibCalls.cpp
llvm/test/Transforms/InferFunctionAttrs/annotate.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index 7274714f82e21..2301be6977cef 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -802,6 +802,7 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
Changed |= setRetAndArgsNoUndef(F);
Changed |= setDoesNotThrow(F);
Changed |= setDoesNotCapture(F, 2);
+ Changed |= setOnlyWritesMemory(F, 0);
break;
case LibFunc_fread:
case LibFunc_fread_unlocked:
@@ -809,6 +810,7 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
Changed |= setDoesNotThrow(F);
Changed |= setDoesNotCapture(F, 0);
Changed |= setDoesNotCapture(F, 3);
+ Changed |= setOnlyWritesMemory(F, 0);
break;
case LibFunc_fwrite:
case LibFunc_fwrite_unlocked:
@@ -816,7 +818,7 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
Changed |= setDoesNotThrow(F);
Changed |= setDoesNotCapture(F, 0);
Changed |= setDoesNotCapture(F, 3);
- // FIXME: readonly #1?
+ Changed |= setOnlyReadsMemory(F, 0);
break;
case LibFunc_fputs:
case LibFunc_fputs_unlocked:
@@ -1150,6 +1152,8 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
break;
case LibFunc_abort:
Changed |= setIsCold(F);
+ Changed |= setNoReturn(F);
+ Changed |= setDoesNotThrow(F);
break;
case LibFunc_terminate:
Changed |= setIsCold(F);
@@ -1166,12 +1170,6 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
Changed |= setDoesNotAccessMemory(F);
Changed |= setDoesNotThrow(F);
break;
- case LibFunc_ldexp:
- case LibFunc_ldexpf:
- case LibFunc_ldexpl:
- Changed |= setOnlyWritesErrnoMemory(F);
- Changed |= setWillReturn(F);
- break;
case LibFunc_acos:
case LibFunc_acosf:
case LibFunc_acosh:
@@ -1228,6 +1226,9 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
case LibFunc_hypot:
case LibFunc_hypotf:
case LibFunc_hypotl:
+ case LibFunc_ldexp:
+ case LibFunc_ldexpf:
+ case LibFunc_ldexpl:
case LibFunc_log:
case LibFunc_log10:
case LibFunc_log10f:
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index 2b9cfca03cde2..55896b72d3a57 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -428,7 +428,7 @@ declare i32 @fgetc(ptr)
; CHECK: declare noundef i32 @fgetpos(ptr noundef captures(none), ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare i32 @fgetpos(ptr, ptr)
-; CHECK: declare noundef ptr @fgets(ptr noundef, i32 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
+; CHECK: declare noundef ptr @fgets(ptr noundef writeonly, i32 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare ptr @fgets(ptr, i32, ptr)
; CHECK: declare noundef i32 @fileno(ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
@@ -494,7 +494,7 @@ declare i32 @fputc(i32, ptr)
; CHECK: declare noundef i32 @fputs(ptr noundef readonly captures(none), ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare i32 @fputs(ptr, ptr)
-; CHECK: declare noundef i64 @fread(ptr noundef captures(none), i64 noundef, i64 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
+; CHECK: declare noundef i64 @fread(ptr noundef writeonly captures(none), i64 noundef, i64 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare i64 @fread(ptr, i64, i64, ptr)
; CHECK: declare void @free(ptr allocptr noundef captures(none)) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND_FREE_FAMILY_MALLOC:#[0-9]+]]
@@ -554,7 +554,7 @@ declare i32 @ftrylockfile(ptr)
; CHECK: declare void @funlockfile(ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare void @funlockfile(ptr)
-; CHECK: declare noundef i64 @fwrite(ptr noundef captures(none), i64 noundef, i64 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
+; CHECK: declare noundef i64 @fwrite(ptr noundef readonly captures(none), i64 noundef, i64 noundef, ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
declare i64 @fwrite(ptr, i64, i64, ptr)
; CHECK: declare noundef i32 @getc(ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
@@ -610,13 +610,13 @@ declare i64 @labs(i64)
; CHECK: declare noundef i32 @lchown(ptr noundef readonly captures(none), i32 noundef, i32 noundef) [[NOFREE_NOUNWIND]]
declare i32 @lchown(ptr, i32, i32)
-; CHECK: declare double @ldexp(double, i32) [[ERRNOMEMONLY_NOFREE_WILLRETURN:#[0-9]+]]
+; CHECK: declare double @ldexp(double, i32) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
declare double @ldexp(double, i32)
-; CHECK: declare float @ldexpf(float, i32) [[ERRNOMEMONLY_NOFREE_WILLRETURN:#[0-9]+]]
+; CHECK: declare float @ldexpf(float, i32) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
declare float @ldexpf(float, i32)
-; CHECK: declare x86_fp80 @ldexpl(x86_fp80, i32) [[ERRNOMEMONLY_NOFREE_WILLRETURN:#[0-9]+]]
+; CHECK: declare x86_fp80 @ldexpl(x86_fp80, i32) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
declare x86_fp80 @ldexpl(x86_fp80, i32)
; CHECK: declare i64 @llabs(i64) [[MEMNONE_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
@@ -1155,7 +1155,7 @@ declare i32 @vsscanf(ptr, ptr, ptr)
; CHECK: declare noundef i64 @write(i32 noundef, ptr noundef readonly captures(none), i64 noundef) [[NOFREE]]
declare i64 @write(i32, ptr, i64)
-; CHECK: declare void @abort() [[NOFREE_COLD:#[0-9]+]]
+; CHECK: declare void @abort() [[NOFREE_COLD_NORETURN_NOUNWIND:#[0-9]+]]
declare void @abort()
; CHECK: declare void @__cxa_throw(ptr, ptr, ptr) [[COLD_NORETURN:#[0-9]+]]
@@ -1193,7 +1193,6 @@ declare void @memset_pattern16(ptr, ptr, i64)
; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]] = { mustprogress nofree nounwind willreturn memory(argmem: readwrite) }
; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY]] = { nofree nounwind memory(read) }
; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND_FREE_FAMILY_MALLOC]] = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" }
-; CHECK-DAG: attributes [[ERRNOMEMONLY_NOFREE_WILLRETURN]] = { mustprogress nofree willreturn memory(errnomem: write) }
; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND_ALLOCUNINIT_ALLOCSIZE0_FAMILY_MALLOC]] = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" }
; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { mustprogress nofree nounwind willreturn memory(argmem: read) }
; CHECK-DAG: attributes [[NOFREE]] = { nofree }
@@ -1201,7 +1200,7 @@ declare void @memset_pattern16(ptr, ptr, i64)
; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND_REALLOC_ALLOCSIZE1_FAMILY_MALLOC]] = { mustprogress nounwind willreturn allockind("realloc") allocsize(1) memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" }
; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND_REALLOC_ALLOCSIZE12_FAMILY_MALLOC]] = { mustprogress nounwind willreturn allockind("realloc") allocsize(1,2) memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" }
; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN_FAMILY_MALLOC]] = { mustprogress nofree nounwind willreturn memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" }
-; CHECK-DAG: attributes [[NOFREE_COLD]] = { cold nofree }
+; CHECK-DAG: attributes [[NOFREE_COLD_NORETURN_NOUNWIND]] = { cold nofree noreturn nounwind }
; CHECK-DAG: attributes [[NOFREE_COLD_NORETURN]] = { cold nofree noreturn }
; CHECK-DAG: attributes [[COLD_NORETURN]] = { cold noreturn }
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