zahiraam updated this revision to Diff 476913.
zahiraam marked 6 inline comments as done.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D136176/new/
https://reviews.llvm.org/D136176
Files:
clang/docs/UsersManual.rst
clang/include/clang/Basic/FPOptions.def
clang/include/clang/Basic/LangOptions.def
clang/include/clang/Basic/LangOptions.h
clang/include/clang/Driver/Options.td
clang/lib/CodeGen/CGExprScalar.cpp
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/CodeGen/X86/fexcess-precision.c
clang/test/Driver/clang_f_opts.c
clang/test/Driver/fexcess-precision.c
Index: clang/test/Driver/fexcess-precision.c
===================================================================
--- /dev/null
+++ clang/test/Driver/fexcess-precision.c
@@ -0,0 +1,30 @@
+// RUN: %clang -### -target i386 -fexcess-precision=fast -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-FAST %s
+// RUN: %clang -### -target i386 -fexcess-precision=standard -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-STD %s
+
+// RUN: %clang -### -target x86_64 -fexcess-precision=fast -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-FAST %s
+// RUN: %clang -### -target x86_64 -fexcess-precision=standard -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-STD %s
+
+// RUN: %clang -### -target i386 -fexcess-precision=none -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-ERR-ARG %s
+
+// RUN: %clang -### -target x86_64 -fexcess-precision=none -c %s 2>&1 \
+// RUN: | FileCheck --check-prefixes=CHECK-ERR-ARG %s
+
+// RUN: %clang -### -target i386 -fexcess-precision=none -c %s 2>&1 \
+// RUN: | FileCheck --check-prefixes=CHECK-ERR-ARG %s
+
+// RUN: %clang -### -target i386 -fexcess-precision=16 -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-ERR-I386 %s
+
+// RUN: %clang -### -target x86_64 -fexcess-precision=16 -c %s 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-ERR-X64 %s
+
+// CHECK-FAST: "-ffloat16-excess-precision=fast"
+// CHECK-STD: "-ffloat16-excess-precision=standard"
+// CHECK-ERR-I386: error: unsupported option '-fexcess-precision=16' for target 'i386'
+// CHECK-ERR-X64: error: unsupported option '-fexcess-precision=16' for target 'x86_64'
+// CHECK-ERR-ARG: unsupported argument 'none' to option '-fexcess-precision='
Index: clang/test/Driver/clang_f_opts.c
===================================================================
--- clang/test/Driver/clang_f_opts.c
+++ clang/test/Driver/clang_f_opts.c
@@ -398,7 +398,7 @@
// CHECK-WARNING-DAG: optimization flag '-falign-loops' is not supported
// CHECK-WARNING-DAG: optimization flag '-falign-jumps' is not supported
// CHECK-WARNING-DAG: optimization flag '-falign-jumps=100' is not supported
-// CHECK-WARNING-DAG: optimization flag '-fexcess-precision=100' is not supported
+// CHECK-WARNING-DAG: unsupported argument '100' to option '-fexcess-precision='
// CHECK-WARNING-DAG: optimization flag '-fbranch-count-reg' is not supported
// CHECK-WARNING-DAG: optimization flag '-fcaller-saves' is not supported
// CHECK-WARNING-DAG: optimization flag '-fno-default-inline' is not supported
Index: clang/test/CodeGen/X86/fexcess-precision.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/X86/fexcess-precision.c
@@ -0,0 +1,286 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=fast \
+// RUN: -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=standard \
+// RUN: -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-NO-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=fast \
+// RUN: -emit-llvm -ffp-eval-method=source -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=standard \
+// RUN: -emit-llvm -ffp-eval-method=source -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -emit-llvm -ffp-eval-method=source -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-NO-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=fast \
+// RUN: -emit-llvm -ffp-eval-method=double -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-DBL %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=standard \
+// RUN: -emit-llvm -ffp-eval-method=double -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-DBL %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -emit-llvm -ffp-eval-method=double -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-DBL %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=fast \
+// RUN: -emit-llvm -ffp-eval-method=extended -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-FP80 %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=standard \
+// RUN: -emit-llvm -ffp-eval-method=extended -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-FP80 %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -emit-llvm -ffp-eval-method=extended -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-EXT-FP80 %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -ffp-contract=on -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-CONTRACT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -fmath-errno -ffp-contract=on -fno-rounding-math \
+// RUN: -ffp-eval-method=source -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-CONTRACT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -fmath-errno -ffp-contract=on -fno-rounding-math \
+// RUN: -ffp-eval-method=double -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-CONTRACT-DBL %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -fmath-errno -ffp-contract=on -fno-rounding-math \
+// RUN: -ffp-eval-method=extended -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-CONTRACT-EXT %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -ffloat16-excess-precision=none \
+// RUN: -fapprox-func -fmath-errno -fno-signed-zeros -mreassociate \
+// RUN: -freciprocal-math -ffp-contract=on -fno-rounding-math \
+// RUN: -funsafe-math-optimizations -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=CHECK-UNSAFE %s
+
+// CHECK-EXT-LABEL: @f(
+// CHECK-EXT-NEXT: entry:
+// CHECK-EXT-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-EXT-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-EXT-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-EXT-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-EXT-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-EXT-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-EXT-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-EXT-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-EXT-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-EXT-NEXT: [[EXT:%.*]] = fpext half [[TMP0]] to float
+// CHECK-EXT-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-EXT-NEXT: [[EXT1:%.*]] = fpext half [[TMP1]] to float
+// CHECK-EXT-NEXT: [[MUL:%.*]] = fmul float [[EXT]], [[EXT1]]
+// CHECK-EXT-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-EXT-NEXT: [[EXT2:%.*]] = fpext half [[TMP2]] to float
+// CHECK-EXT-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-EXT-NEXT: [[EXT3:%.*]] = fpext half [[TMP3]] to float
+// CHECK-EXT-NEXT: [[MUL4:%.*]] = fmul float [[EXT2]], [[EXT3]]
+// CHECK-EXT-NEXT: [[ADD:%.*]] = fadd float [[MUL]], [[MUL4]]
+// CHECK-EXT-NEXT: [[UNPROMOTION:%.*]] = fptrunc float [[ADD]] to half
+// CHECK-EXT-NEXT: ret half [[UNPROMOTION]]
+//
+// CHECK-NO-EXT-LABEL: @f(
+// CHECK-NO-EXT-NEXT: entry:
+// CHECK-NO-EXT-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-NO-EXT-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-NO-EXT-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-NO-EXT-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-NO-EXT-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-NO-EXT-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-NO-EXT-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-NO-EXT-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-NO-EXT-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-NO-EXT-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-NO-EXT-NEXT: [[MUL:%.*]] = fmul half [[TMP0]], [[TMP1]]
+// CHECK-NO-EXT-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-NO-EXT-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-NO-EXT-NEXT: [[MUL1:%.*]] = fmul half [[TMP2]], [[TMP3]]
+// CHECK-NO-EXT-NEXT: [[ADD:%.*]] = fadd half [[MUL]], [[MUL1]]
+// CHECK-NO-EXT-NEXT: ret half [[ADD]]
+//
+// CHECK-EXT-DBL-LABEL: @f(
+// CHECK-EXT-DBL-NEXT: entry:
+// CHECK-EXT-DBL-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-EXT-DBL-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-EXT-DBL-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-EXT-DBL-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-EXT-DBL-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-EXT-DBL-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-EXT-DBL-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-EXT-DBL-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-EXT-DBL-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-EXT-DBL-NEXT: [[CONV:%.*]] = fpext half [[TMP0]] to double
+// CHECK-EXT-DBL-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-EXT-DBL-NEXT: [[CONV1:%.*]] = fpext half [[TMP1]] to double
+// CHECK-EXT-DBL-NEXT: [[MUL:%.*]] = fmul double [[CONV]], [[CONV1]]
+// CHECK-EXT-DBL-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-EXT-DBL-NEXT: [[CONV2:%.*]] = fpext half [[TMP2]] to double
+// CHECK-EXT-DBL-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-EXT-DBL-NEXT: [[CONV3:%.*]] = fpext half [[TMP3]] to double
+// CHECK-EXT-DBL-NEXT: [[MUL4:%.*]] = fmul double [[CONV2]], [[CONV3]]
+// CHECK-EXT-DBL-NEXT: [[ADD:%.*]] = fadd double [[MUL]], [[MUL4]]
+// CHECK-EXT-DBL-NEXT: [[CONV5:%.*]] = fptrunc double [[ADD]] to half
+// CHECK-EXT-DBL-NEXT: ret half [[CONV5]]
+//
+// CHECK-EXT-FP80-LABEL: @f(
+// CHECK-EXT-FP80-NEXT: entry:
+// CHECK-EXT-FP80-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-EXT-FP80-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-EXT-FP80-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-EXT-FP80-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-EXT-FP80-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-EXT-FP80-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-EXT-FP80-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-EXT-FP80-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-EXT-FP80-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-EXT-FP80-NEXT: [[CONV:%.*]] = fpext half [[TMP0]] to x86_fp80
+// CHECK-EXT-FP80-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-EXT-FP80-NEXT: [[CONV1:%.*]] = fpext half [[TMP1]] to x86_fp80
+// CHECK-EXT-FP80-NEXT: [[MUL:%.*]] = fmul x86_fp80 [[CONV]], [[CONV1]]
+// CHECK-EXT-FP80-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-EXT-FP80-NEXT: [[CONV2:%.*]] = fpext half [[TMP2]] to x86_fp80
+// CHECK-EXT-FP80-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-EXT-FP80-NEXT: [[CONV3:%.*]] = fpext half [[TMP3]] to x86_fp80
+// CHECK-EXT-FP80-NEXT: [[MUL4:%.*]] = fmul x86_fp80 [[CONV2]], [[CONV3]]
+// CHECK-EXT-FP80-NEXT: [[ADD:%.*]] = fadd x86_fp80 [[MUL]], [[MUL4]]
+// CHECK-EXT-FP80-NEXT: [[CONV5:%.*]] = fptrunc x86_fp80 [[ADD]] to half
+// CHECK-EXT-FP80-NEXT: ret half [[CONV5]]
+//
+// CHECK-CONTRACT-LABEL: @f(
+// CHECK-CONTRACT-NEXT: entry:
+// CHECK-CONTRACT-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-CONTRACT-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-CONTRACT-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-CONTRACT-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-CONTRACT-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-CONTRACT-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-CONTRACT-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-CONTRACT-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-CONTRACT-NEXT: [[MUL1:%.*]] = fmul half [[TMP2]], [[TMP3]]
+// CHECK-CONTRACT-NEXT: [[TMP4:%.*]] = call half @llvm.fmuladd.f16(half [[TMP0]], half [[TMP1]], half [[MUL1]])
+// CHECK-CONTRACT-NEXT: ret half [[TMP4]]
+//
+// CHECK-CONTRACT-DBL-LABEL: @f(
+// CHECK-CONTRACT-DBL-NEXT: entry:
+// CHECK-CONTRACT-DBL-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-DBL-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-DBL-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-DBL-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-DBL-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: [[CONV:%.*]] = fpext half [[TMP0]] to double
+// CHECK-CONTRACT-DBL-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: [[CONV1:%.*]] = fpext half [[TMP1]] to double
+// CHECK-CONTRACT-DBL-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: [[CONV2:%.*]] = fpext half [[TMP2]] to double
+// CHECK-CONTRACT-DBL-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-CONTRACT-DBL-NEXT: [[CONV3:%.*]] = fpext half [[TMP3]] to double
+// CHECK-CONTRACT-DBL-NEXT: [[MUL4:%.*]] = fmul double [[CONV2]], [[CONV3]]
+// CHECK-CONTRACT-DBL-NEXT: [[TMP4:%.*]] = call double @llvm.fmuladd.f64(double [[CONV]], double [[CONV1]], double [[MUL4]])
+// CHECK-CONTRACT-DBL-NEXT: [[CONV5:%.*]] = fptrunc double [[TMP4]] to half
+// CHECK-CONTRACT-DBL-NEXT: ret half [[CONV5]]
+//
+// CHECK-CONTRACT-EXT-LABEL: @f(
+// CHECK-CONTRACT-EXT-NEXT: entry:
+// CHECK-CONTRACT-EXT-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-EXT-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-EXT-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-EXT-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-CONTRACT-EXT-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: [[CONV:%.*]] = fpext half [[TMP0]] to x86_fp80
+// CHECK-CONTRACT-EXT-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: [[CONV1:%.*]] = fpext half [[TMP1]] to x86_fp80
+// CHECK-CONTRACT-EXT-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: [[CONV2:%.*]] = fpext half [[TMP2]] to x86_fp80
+// CHECK-CONTRACT-EXT-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-CONTRACT-EXT-NEXT: [[CONV3:%.*]] = fpext half [[TMP3]] to x86_fp80
+// CHECK-CONTRACT-EXT-NEXT: [[MUL4:%.*]] = fmul x86_fp80 [[CONV2]], [[CONV3]]
+// CHECK-CONTRACT-EXT-NEXT: [[TMP4:%.*]] = call x86_fp80 @llvm.fmuladd.f80(x86_fp80 [[CONV]], x86_fp80 [[CONV1]], x86_fp80 [[MUL4]])
+// CHECK-CONTRACT-EXT-NEXT: [[CONV5:%.*]] = fptrunc x86_fp80 [[TMP4]] to half
+// CHECK-CONTRACT-EXT-NEXT: ret half [[CONV5]]
+//
+// CHECK-UNSAFE-LABEL: @f(
+// CHECK-UNSAFE-NEXT: entry:
+// CHECK-UNSAFE-NEXT: [[A_ADDR:%.*]] = alloca half
+// CHECK-UNSAFE-NEXT: [[B_ADDR:%.*]] = alloca half
+// CHECK-UNSAFE-NEXT: [[C_ADDR:%.*]] = alloca half
+// CHECK-UNSAFE-NEXT: [[D_ADDR:%.*]] = alloca half
+// CHECK-UNSAFE-NEXT: store half [[A:%.*]], ptr [[A_ADDR]]
+// CHECK-UNSAFE-NEXT: store half [[B:%.*]], ptr [[B_ADDR]]
+// CHECK-UNSAFE-NEXT: store half [[C:%.*]], ptr [[C_ADDR]]
+// CHECK-UNSAFE-NEXT: store half [[D:%.*]], ptr [[D_ADDR]]
+// CHECK-UNSAFE-NEXT: [[TMP0:%.*]] = load half, ptr [[A_ADDR]]
+// CHECK-UNSAFE-NEXT: [[TMP1:%.*]] = load half, ptr [[B_ADDR]]
+// CHECK-UNSAFE-NEXT: [[TMP2:%.*]] = load half, ptr [[C_ADDR]]
+// CHECK-UNSAFE-NEXT: [[TMP3:%.*]] = load half, ptr [[D_ADDR]]
+// CHECK-UNSAFE-NEXT: [[MUL1:%.*]] = fmul reassoc nsz arcp afn half [[TMP2]], [[TMP3]]
+// CHECK-UNSAFE-NEXT: [[TMP4:%.*]] = call reassoc nsz arcp afn half @llvm.fmuladd.f16(half [[TMP0]], half [[TMP1]], half [[MUL1]])
+// CHECK-UNSAFE-NEXT: ret half [[TMP4]]
+//
+_Float16 f(_Float16 a, _Float16 b, _Float16 c, _Float16 d) {
+ return a * b + c * d;
+}
+
+// CHECK-EXT-LABEL: @getFEM(
+// CHECK-EXT-NEXT: entry:
+// CHECK-EXT-NEXT: ret i32 0
+//
+// CHECK-NO-EXT-LABEL: @getFEM(
+// CHECK-NO-EXT-NEXT: entry:
+// CHECK-NO-EXT-NEXT: ret i32 0
+//
+// CHECK-EXT-DBL-LABEL: @getFEM(
+// CHECK-EXT-DBL-NEXT: entry:
+// CHECK-EXT-DBL-NEXT: ret i32 1
+//
+// CHECK-EXT-FP80-LABEL: @getFEM(
+// CHECK-EXT-FP80-NEXT: entry:
+// CHECK-EXT-FP80-NEXT: ret i32 2
+//
+// CHECK-CONTRACT-LABEL: @getFEM(
+// CHECK-CONTRACT-NEXT: entry:
+// CHECK-CONTRACT-NEXT: ret i32 0
+//
+// CHECK-CONTRACT-DBL-LABEL: @getFEM(
+// CHECK-CONTRACT-DBL-NEXT: entry:
+// CHECK-CONTRACT-DBL-NEXT: ret i32 1
+//
+// CHECK-CONTRACT-EXT-LABEL: @getFEM(
+// CHECK-CONTRACT-EXT-NEXT: entry:
+// CHECK-CONTRACT-EXT-NEXT: ret i32 2
+//
+// CHECK-UNSAFE-LABEL: @getFEM(
+// CHECK-UNSAFE-NEXT: entry:
+// CHECK-UNSAFE-NEXT: ret i32 -1
+//
+int getFEM() {
+ return __FLT_EVAL_METHOD__;
+}
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -2792,6 +2792,7 @@
!JA.isOffloading(Action::OFK_HIP))
FPContract = "on";
bool StrictFPModel = false;
+ StringRef Float16ExcessPrecision = "";
if (const Arg *A = Args.getLastArg(options::OPT_flimited_precision_EQ)) {
CmdArgs.push_back("-mlimit-float-precision");
@@ -2987,6 +2988,27 @@
break;
}
+ case options::OPT_fexcess_precision_EQ: {
+ StringRef Val = A->getValue();
+ const llvm::Triple::ArchType Arch = TC.getArch();
+ if ((Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64) &&
+ Val.equals("16"))
+ D.Diag(diag::err_drv_unsupported_opt_for_target)
+ << A->getAsString(Args) << TC.getTriple().str();
+ if (Val.equals("standard") || Val.equals("fast")) {
+ Float16ExcessPrecision = Val;
+ } else {
+ if (Val.equals("16"))
+ // To make it GCC compatible, allow the value of "16" which
+ // means disable excess precision, the same meaning than clang's
+ // equivalent value "none".
+ Float16ExcessPrecision = "none";
+ else
+ D.Diag(diag::err_drv_unsupported_option_argument)
+ << A->getSpelling() << Val;
+ }
+ break;
+ }
case options::OPT_ffinite_math_only:
HonorINFs = false;
HonorNaNs = false;
@@ -3154,6 +3176,10 @@
if (!FPEvalMethod.empty())
CmdArgs.push_back(Args.MakeArgString("-ffp-eval-method=" + FPEvalMethod));
+ if (!Float16ExcessPrecision.empty())
+ CmdArgs.push_back(Args.MakeArgString("-ffloat16-excess-precision=" +
+ Float16ExcessPrecision));
+
ParseMRecip(D, Args, CmdArgs);
// -ffast-math enables the __FAST_MATH__ preprocessor macro, but check for the
Index: clang/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- clang/lib/CodeGen/CGExprScalar.cpp
+++ clang/lib/CodeGen/CGExprScalar.cpp
@@ -814,7 +814,11 @@
Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
QualType getPromotionType(QualType Ty) {
- if (CGF.getTarget().shouldEmitFloat16WithExcessPrecision()) {
+ LangOptions::ExcessPrecisionKind Precision =
+ CGF.getContext().getLangOpts().getExcessPrecision();
+ if (CGF.getTarget().shouldEmitFloat16WithExcessPrecision() &&
+ (Precision == LangOptions::ExcessPrecisionKind::FPP_Standard ||
+ Precision == LangOptions::ExcessPrecisionKind::FPP_Fast)) {
if (Ty->isAnyComplexType()) {
QualType ElementType = Ty->castAs<ComplexType>()->getElementType();
if (ElementType->isFloat16Type())
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1570,8 +1570,22 @@
def fignore_exceptions : Flag<["-"], "fignore-exceptions">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Enable support for ignoring exception handling constructs">,
MarshallingInfoFlag<LangOpts<"IgnoreExceptions">>;
-def fexcess_precision_EQ : Joined<["-"], "fexcess-precision=">,
- Group<clang_ignored_gcc_optimization_f_Group>;
+def fexcess_precision_EQ : Joined<["-"], "fexcess-precision=">, Group<f_Group>,
+ HelpText<"Allows control over excess precision on targets where native "
+ "support for the precision types is not available. By default, excess "
+ "precision is used to calculate intermediate results following the "
+ "rules specified in ISO C99.">,
+ Values<"standard,fast,none">, NormalizedValuesScope<"LangOptions">,
+ NormalizedValues<["FPP_Standard", "FPP_Fast", "FPP_None"]>;
+def ffloat16_excess_precision_EQ : Joined<["-"], "ffloat16-excess-precision=">,
+ Group<f_Group>, Flags<[CC1Option, NoDriverOption]>,
+ HelpText<"Allows control over excess precision on targets where native "
+ "support for Float16 precision types is not available. By default, excess "
+ "precision is used to calculate intermediate results following the "
+ "rules specified in ISO C99.">,
+ Values<"standard,fast,none">, NormalizedValuesScope<"LangOptions">,
+ NormalizedValues<["FPP_Standard", "FPP_Fast", "FPP_None"]>,
+ MarshallingInfoEnum<LangOpts<"ExcessPrecision">, "FPP_Standard">;
def : Flag<["-"], "fexpensive-optimizations">, Group<clang_ignored_gcc_optimization_f_Group>;
def : Flag<["-"], "fno-expensive-optimizations">, Group<clang_ignored_gcc_optimization_f_Group>;
def fextdirs_EQ : Joined<["-"], "fextdirs=">, Group<f_Group>;
Index: clang/include/clang/Basic/LangOptions.h
===================================================================
--- clang/include/clang/Basic/LangOptions.h
+++ clang/include/clang/Basic/LangOptions.h
@@ -298,6 +298,8 @@
FEM_UnsetOnCommandLine = 3
};
+ enum ExcessPrecisionKind { FPP_Standard, FPP_Fast, FPP_None };
+
/// Possible exception handling behavior.
enum class ExceptionHandlingKind { None, SjLj, WinEH, DwarfCFI, Wasm };
Index: clang/include/clang/Basic/LangOptions.def
===================================================================
--- clang/include/clang/Basic/LangOptions.def
+++ clang/include/clang/Basic/LangOptions.def
@@ -317,6 +317,7 @@
BENIGN_LANGOPT(RoundingMath, 1, false, "Do not assume default floating-point rounding behavior")
BENIGN_ENUM_LANGOPT(FPExceptionMode, FPExceptionModeKind, 2, FPE_Default, "FP Exception Behavior Mode type")
BENIGN_ENUM_LANGOPT(FPEvalMethod, FPEvalMethodKind, 2, FEM_UnsetOnCommandLine, "FP type used for floating point arithmetic")
+ENUM_LANGOPT(ExcessPrecision, ExcessPrecisionKind, 2, FPP_Standard, "Intermediate truncation behavior for floating point arithmetic")
LANGOPT(NoBitFieldTypeAlign , 1, 0, "bit-field type alignment")
LANGOPT(HexagonQdsp6Compat , 1, 0, "hexagon-qdsp6 backward compatibility")
LANGOPT(ObjCAutoRefCount , 1, 0, "Objective-C automated reference counting")
Index: clang/include/clang/Basic/FPOptions.def
===================================================================
--- clang/include/clang/Basic/FPOptions.def
+++ clang/include/clang/Basic/FPOptions.def
@@ -25,4 +25,5 @@
OPTION(AllowReciprocal, bool, 1, NoSignedZero)
OPTION(AllowApproxFunc, bool, 1, AllowReciprocal)
OPTION(FPEvalMethod, LangOptions::FPEvalMethodKind, 2, AllowApproxFunc)
+OPTION(ExcessPrecision, LangOptions::ExcessPrecisionKind, 2, FPEvalMethod)
#undef OPTION
Index: clang/docs/UsersManual.rst
===================================================================
--- clang/docs/UsersManual.rst
+++ clang/docs/UsersManual.rst
@@ -1728,6 +1728,47 @@
has no effect because the optimizer is prohibited from making unsafe
transformations.
+.. option:: -fexcess-precision:
+
+ The C and C++ standards allow floating-point expressions to be computed as if
+ intermediate results had more precision (and/or a wider range) than the type
+ of the expression strictly allows. This is called excess precision
+ arithmetic.
+ Excess precision arithmetic can improve the accuracy of results (although not
+ always), and it can make computation significantly faster if the target lacks
+ direct hardware support for arithmetic in a particular type. However, it can
+ also undermine strict floating-point reproducibility.
+
+ Under the standards, assignments and explicit casts force the operand to be
+ converted to its formal type, discarding any excess precision. Because data
+ can only flow between statements via an assignment, this means that the use
+ of excess precision arithmetic is a reliable local property of a single
+ statement, and results do not change based on optimization. However, when
+ excess precision arithmetic is in use, Clang does not guarantee strict
+ reproducibility, and future compiler releases may recognize more
+ opportunities to use excess precision arithmetic, e.g. with floating-point
+ builtins.
+
+ Clang does not use excess precision arithmetic for most types or on most
+ targets. For example, even on pre-SSE X86 targets where ``float`` and
+ ``double`` computations must be performed in the 80-bit X87 format, Clang
+ rounds all intermediate results correctly for their type. Clang currently
+ uses excess precision arithmetic by default only for the following types and
+ targets:
+
+ * ``_Float16`` on X86 targets without ``AVX512-FP16``.
+
+ The ``-fexcess-precision=<value>`` option can be used to control the use of
+ excess precision arithmetic. Valid values are:
+
+ * ``standard`` - The default. Allow the use of excess precision arithmetic
+ under the constraints of the C and C++ standards. Has no effect except on
+ the types and targets listed above.
+ * ``fast`` - Accepted for GCC compatibility, but currently treated as an
+ alias for ``standard``.
+ * ``16`` - Forces ``_Float16`` operations to be emitted without using excess
+ precision arithmetic.
+
.. _crtfastmath.o:
A note about ``crtfastmath.o``
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