Skip to content

Commit 1bf7f4d

Browse files
LebedevRImemfrob
LebedevRI
authored and
memfrob
committed
Revert @llvm.isnan intrinsic patchset.
Please refer to https://lists.llvm.org/pipermail/llvm-dev/2021-September/152440.html (and that whole thread.) TLDR: the original patch had no prior RFC, yet it had some changes that really need a proper RFC discussion. It won't be productive to discuss such an RFC, once it's actually posted, while said patch is already committed, because that introduces bias towards already-committed stuff, and the tree is potentially in broken state meanwhile. While the end result of discussion may lead back to the current design, it may also not lead to the current design. Therefore i take it upon myself to revert the tree back to last known good state. This reverts commit 4c4093e6e39fe6601f9c95a95a6bc242ef648cd5. This reverts commit 0a2b1ba33ae6dcaedb81417f7c4cc714f72a5968. This reverts commit d9873711cb03ac7aedcaadcba42f82c66e962e6e. This reverts commit 791006fb8c6fff4f33c33cb513a96b1d3f94c767. This reverts commit c22b64ef66f7518abb6f022fcdfd86d16c764caf. This reverts commit 72ebcd3198327da12804305bda13d9b7088772a8. This reverts commit 5fa6039a5fc1b6392a3c9a3326a76604e0cb1001. This reverts commit 9efda541bfbd145de90f7db38d935db6246dc45a. This reverts commit 94d3ff09cfa8d7aecf480e54da9a5334e262e76b.
1 parent c353346 commit 1bf7f4d

39 files changed

+158
-2997
lines changed

‎clang/lib/CodeGen/CGBuiltin.cpp

Lines changed: 24 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -3068,17 +3068,37 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
30683068
// ZExt bool to int type.
30693069
return RValue::get(Builder.CreateZExt(LHS, ConvertType(E->getType())));
30703070
}
3071-
30723071
case Builtin::BI__builtin_isnan: {
30733072
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(*this, E);
30743073
Value *V = EmitScalarExpr(E->getArg(0));
3074+
llvm::Type *Ty = V->getType();
3075+
const llvm::fltSemantics &Semantics = Ty->getFltSemantics();
3076+
if (!Builder.getIsFPConstrained() ||
3077+
Builder.getDefaultConstrainedExcept() == fp::ebIgnore ||
3078+
!Ty->isIEEE()) {
3079+
V = Builder.CreateFCmpUNO(V, V, "cmp");
3080+
return RValue::get(Builder.CreateZExt(V, ConvertType(E->getType())));
3081+
}
30753082

30763083
if (Value *Result = getTargetHooks().testFPKind(V, BuiltinID, Builder, CGM))
30773084
return RValue::get(Result);
30783085

3079-
Function *F = CGM.getIntrinsic(Intrinsic::isnan, V->getType());
3080-
Value *Call = Builder.CreateCall(F, V);
3081-
return RValue::get(Builder.CreateZExt(Call, ConvertType(E->getType())));
3086+
// NaN has all exp bits set and a non zero significand. Therefore:
3087+
// isnan(V) == ((exp mask - (abs(V) & exp mask)) < 0)
3088+
unsigned bitsize = Ty->getScalarSizeInBits();
3089+
llvm::IntegerType *IntTy = Builder.getIntNTy(bitsize);
3090+
Value *IntV = Builder.CreateBitCast(V, IntTy);
3091+
APInt AndMask = APInt::getSignedMaxValue(bitsize);
3092+
Value *AbsV =
3093+
Builder.CreateAnd(IntV, llvm::ConstantInt::get(IntTy, AndMask));
3094+
APInt ExpMask = APFloat::getInf(Semantics).bitcastToAPInt();
3095+
Value *Sub =
3096+
Builder.CreateSub(llvm::ConstantInt::get(IntTy, ExpMask), AbsV);
3097+
// V = sign bit (Sub) <=> V = (Sub < 0)
3098+
V = Builder.CreateLShr(Sub, llvm::ConstantInt::get(IntTy, bitsize - 1));
3099+
if (bitsize > 32)
3100+
V = Builder.CreateTrunc(V, ConvertType(E->getType()));
3101+
return RValue::get(V);
30823102
}
30833103

30843104
case Builtin::BI__builtin_matrix_transpose: {

‎clang/test/CodeGen/X86/strictfp_builtins.c

Lines changed: 20 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,7 @@ int printf(const char *, ...);
1717
// CHECK-NEXT: store i32 [[X:%.*]], i32* [[X_ADDR]], align 4
1818
// CHECK-NEXT: [[TMP0:%.*]] = load i8*, i8** [[STR_ADDR]], align 8
1919
// CHECK-NEXT: [[TMP1:%.*]] = load i32, i32* [[X_ADDR]], align 4
20-
// CHECK-NEXT: [[CALL:%.*]] = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8* [[TMP0]], i32 [[TMP1]]) #[[ATTR3:[0-9]+]]
20+
// CHECK-NEXT: [[CALL:%.*]] = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8* [[TMP0]], i32 [[TMP1]]) [[ATTR4:#.*]]
2121
// CHECK-NEXT: ret void
2222
//
2323
void p(char *str, int x) {
@@ -29,13 +29,13 @@ void p(char *str, int x) {
2929
// CHECK-LABEL: @test_long_double_isinf(
3030
// CHECK-NEXT: entry:
3131
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca x86_fp80, align 16
32-
// CHECK-NEXT: store x86_fp80 [[LD:%.*]], x86_fp80* [[LD_ADDR]], align 16
32+
// CHECK-NEXT: store x86_fp80 [[D:%.*]], x86_fp80* [[LD_ADDR]], align 16
3333
// CHECK-NEXT: [[TMP0:%.*]] = load x86_fp80, x86_fp80* [[LD_ADDR]], align 16
34-
// CHECK-NEXT: [[TMP1:%.*]] = bitcast x86_fp80 [[TMP0]] to i80
35-
// CHECK-NEXT: [[TMP2:%.*]] = shl i80 [[TMP1]], 1
36-
// CHECK-NEXT: [[TMP3:%.*]] = icmp eq i80 [[TMP2]], -18446744073709551616
37-
// CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i32
38-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32 [[TMP4]]) #[[ATTR3]]
34+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast x86_fp80 [[TMP0]] to i80
35+
// CHECK-NEXT: [[SHL1:%.*]] = shl i80 [[BITCAST]], 1
36+
// CHECK-NEXT: [[CMP:%.*]] = icmp eq i80 [[SHL1]], -18446744073709551616
37+
// CHECK-NEXT: [[RES:%.*]] = zext i1 [[CMP]] to i32
38+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.[[#STRID:1]], i64 0, i64 0), i32 [[RES]]) [[ATTR4]]
3939
// CHECK-NEXT: ret void
4040
//
4141
void test_long_double_isinf(long double ld) {
@@ -47,13 +47,13 @@ void test_long_double_isinf(long double ld) {
4747
// CHECK-LABEL: @test_long_double_isfinite(
4848
// CHECK-NEXT: entry:
4949
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca x86_fp80, align 16
50-
// CHECK-NEXT: store x86_fp80 [[LD:%.*]], x86_fp80* [[LD_ADDR]], align 16
50+
// CHECK-NEXT: store x86_fp80 [[D:%.*]], x86_fp80* [[LD_ADDR]], align 16
5151
// CHECK-NEXT: [[TMP0:%.*]] = load x86_fp80, x86_fp80* [[LD_ADDR]], align 16
52-
// CHECK-NEXT: [[TMP1:%.*]] = bitcast x86_fp80 [[TMP0]] to i80
53-
// CHECK-NEXT: [[TMP2:%.*]] = shl i80 [[TMP1]], 1
54-
// CHECK-NEXT: [[TMP3:%.*]] = icmp ult i80 [[TMP2]], -18446744073709551616
55-
// CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i32
56-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0), i32 [[TMP4]]) #[[ATTR3]]
52+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast x86_fp80 [[TMP0]] to i80
53+
// CHECK-NEXT: [[SHL1:%.*]] = shl i80 [[BITCAST]], 1
54+
// CHECK-NEXT: [[CMP:%.*]] = icmp ult i80 [[SHL1]], -18446744073709551616
55+
// CHECK-NEXT: [[RES:%.*]] = zext i1 [[CMP]] to i32
56+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.[[#STRID:STRID+1]], i64 0, i64 0), i32 [[RES]]) [[ATTR4]]
5757
// CHECK-NEXT: ret void
5858
//
5959
void test_long_double_isfinite(long double ld) {
@@ -65,11 +65,14 @@ void test_long_double_isfinite(long double ld) {
6565
// CHECK-LABEL: @test_long_double_isnan(
6666
// CHECK-NEXT: entry:
6767
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca x86_fp80, align 16
68-
// CHECK-NEXT: store x86_fp80 [[LD:%.*]], x86_fp80* [[LD_ADDR]], align 16
68+
// CHECK-NEXT: store x86_fp80 [[D:%.*]], x86_fp80* [[LD_ADDR]], align 16
6969
// CHECK-NEXT: [[TMP0:%.*]] = load x86_fp80, x86_fp80* [[LD_ADDR]], align 16
70-
// CHECK-NEXT: [[TMP1:%.*]] = call i1 @llvm.isnan.f80(x86_fp80 [[TMP0]]) #[[ATTR3]]
71-
// CHECK-NEXT: [[TMP2:%.*]] = zext i1 [[TMP1]] to i32
72-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.3, i64 0, i64 0), i32 [[TMP2]]) #[[ATTR3]]
70+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast x86_fp80 [[TMP0]] to i80
71+
// CHECK-NEXT: [[ABS:%.*]] = and i80 [[BITCAST]], 604462909807314587353087
72+
// CHECK-NEXT: [[TMP1:%.*]] = sub i80 604453686435277732577280, [[ABS]]
73+
// CHECK-NEXT: [[ISNAN:%.*]] = lshr i80 [[TMP1]], 79
74+
// CHECK-NEXT: [[RES:%.*]] = trunc i80 [[ISNAN]] to i32
75+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.[[#STRID:STRID+1]], i64 0, i64 0), i32 [[RES]]) [[ATTR4]]
7376
// CHECK-NEXT: ret void
7477
//
7578
void test_long_double_isnan(long double ld) {

‎clang/test/CodeGen/aarch64-strictfp-builtins.c

Lines changed: 20 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,3 @@
1-
// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
21
// RUN: %clang_cc1 %s -emit-llvm -ffp-exception-behavior=maytrap -fexperimental-strict-floating-point -o - -triple arm64-none-linux-gnu | FileCheck %s
32

43
// Test that the constrained intrinsics are picking up the exception
@@ -16,7 +15,7 @@ int printf(const char *, ...);
1615
// CHECK-NEXT: store i32 [[X:%.*]], i32* [[X_ADDR]], align 4
1716
// CHECK-NEXT: [[TMP0:%.*]] = load i8*, i8** [[STR_ADDR]], align 8
1817
// CHECK-NEXT: [[TMP1:%.*]] = load i32, i32* [[X_ADDR]], align 4
19-
// CHECK-NEXT: [[CALL:%.*]] = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8* [[TMP0]], i32 [[TMP1]]) #[[ATTR3:[0-9]+]]
18+
// CHECK-NEXT: [[CALL:%.*]] = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0), i8* [[TMP0]], i32 [[TMP1]]) [[ATTR4:#.*]]
2019
// CHECK-NEXT: ret void
2120
//
2221
void p(char *str, int x) {
@@ -28,13 +27,13 @@ void p(char *str, int x) {
2827
// CHECK-LABEL: @test_long_double_isinf(
2928
// CHECK-NEXT: entry:
3029
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca fp128, align 16
31-
// CHECK-NEXT: store fp128 [[LD:%.*]], fp128* [[LD_ADDR]], align 16
30+
// CHECK-NEXT: store fp128 [[D:%.*]], fp128* [[LD_ADDR]], align 16
3231
// CHECK-NEXT: [[TMP0:%.*]] = load fp128, fp128* [[LD_ADDR]], align 16
33-
// CHECK-NEXT: [[TMP1:%.*]] = bitcast fp128 [[TMP0]] to i128
34-
// CHECK-NEXT: [[TMP2:%.*]] = shl i128 [[TMP1]], 1
35-
// CHECK-NEXT: [[TMP3:%.*]] = icmp eq i128 [[TMP2]], -10384593717069655257060992658440192
36-
// CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i32
37-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32 [[TMP4]]) #[[ATTR3]]
32+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast fp128 [[TMP0]] to i128
33+
// CHECK-NEXT: [[SHL1:%.*]] = shl i128 [[BITCAST]], 1
34+
// CHECK-NEXT: [[CMP:%.*]] = icmp eq i128 [[SHL1]], -10384593717069655257060992658440192
35+
// CHECK-NEXT: [[RES:%.*]] = zext i1 [[CMP]] to i32
36+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.[[#STRID:1]], i64 0, i64 0), i32 [[RES]]) [[ATTR4]]
3837
// CHECK-NEXT: ret void
3938
//
4039
void test_long_double_isinf(long double ld) {
@@ -46,13 +45,13 @@ void test_long_double_isinf(long double ld) {
4645
// CHECK-LABEL: @test_long_double_isfinite(
4746
// CHECK-NEXT: entry:
4847
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca fp128, align 16
49-
// CHECK-NEXT: store fp128 [[LD:%.*]], fp128* [[LD_ADDR]], align 16
48+
// CHECK-NEXT: store fp128 [[D:%.*]], fp128* [[LD_ADDR]], align 16
5049
// CHECK-NEXT: [[TMP0:%.*]] = load fp128, fp128* [[LD_ADDR]], align 16
51-
// CHECK-NEXT: [[TMP1:%.*]] = bitcast fp128 [[TMP0]] to i128
52-
// CHECK-NEXT: [[TMP2:%.*]] = shl i128 [[TMP1]], 1
53-
// CHECK-NEXT: [[TMP3:%.*]] = icmp ult i128 [[TMP2]], -10384593717069655257060992658440192
54-
// CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i32
55-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.2, i64 0, i64 0), i32 [[TMP4]]) #[[ATTR3]]
50+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast fp128 [[TMP0]] to i128
51+
// CHECK-NEXT: [[SHL1:%.*]] = shl i128 [[BITCAST]], 1
52+
// CHECK-NEXT: [[CMP:%.*]] = icmp ult i128 [[SHL1]], -10384593717069655257060992658440192
53+
// CHECK-NEXT: [[RES:%.*]] = zext i1 [[CMP]] to i32
54+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.[[#STRID:STRID+1]], i64 0, i64 0), i32 [[RES]]) [[ATTR4]]
5655
// CHECK-NEXT: ret void
5756
//
5857
void test_long_double_isfinite(long double ld) {
@@ -64,11 +63,14 @@ void test_long_double_isfinite(long double ld) {
6463
// CHECK-LABEL: @test_long_double_isnan(
6564
// CHECK-NEXT: entry:
6665
// CHECK-NEXT: [[LD_ADDR:%.*]] = alloca fp128, align 16
67-
// CHECK-NEXT: store fp128 [[LD:%.*]], fp128* [[LD_ADDR]], align 16
66+
// CHECK-NEXT: store fp128 [[D:%.*]], fp128* [[LD_ADDR]], align 16
6867
// CHECK-NEXT: [[TMP0:%.*]] = load fp128, fp128* [[LD_ADDR]], align 16
69-
// CHECK-NEXT: [[TMP1:%.*]] = call i1 @llvm.isnan.f128(fp128 [[TMP0]]) #[[ATTR3]]
70-
// CHECK-NEXT: [[TMP2:%.*]] = zext i1 [[TMP1]] to i32
71-
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.3, i64 0, i64 0), i32 [[TMP2]]) #[[ATTR3]]
68+
// CHECK-NEXT: [[BITCAST:%.*]] = bitcast fp128 [[TMP0]] to i128
69+
// CHECK-NEXT: [[ABS:%.*]] = and i128 [[BITCAST]], 170141183460469231731687303715884105727
70+
// CHECK-NEXT: [[TMP1:%.*]] = sub i128 170135991163610696904058773219554885632, [[ABS]]
71+
// CHECK-NEXT: [[ISNAN:%.*]] = lshr i128 [[TMP1]], 127
72+
// CHECK-NEXT: [[RES:%.*]] = trunc i128 [[ISNAN]] to i32
73+
// CHECK-NEXT: call void @p(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.[[#STRID:STRID+1]], i64 0, i64 0), i32 [[RES]])
7274
// CHECK-NEXT: ret void
7375
//
7476
void test_long_double_isnan(long double ld) {

0 commit comments

Comments
 (0)