[CodeGen] More consistently expand float ops by default #150597
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These float operations were expanded for scalar f32/f64/f128, but not for f16 and more problematically, not for vectors. A small subset of them was separately set to expand for vectors. Change these to always expand by default, and adjust targets to mark these as legal where necessary instead. This is a much safer default, and avoids unnecessary legalization failures because a target failed to manually mark them as expand. Fixes llvm#110753.
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@llvm/pr-subscribers-llvm-selectiondag @llvm/pr-subscribers-backend-amdgpu Author: Nikita Popov (nikic) ChangesThese float operations were expanded for scalar f32/f64/f128, but not for f16 and more problematically, not for vectors. A small subset of them was separately set to expand for vectors. Change these to always expand by default, and adjust targets to mark these as legal where necessary instead. This is a much safer default, and avoids unnecessary legalization failures because a target failed to manually mark them as expand. Fixes #110753. Full diff: https://github.com/llvm/llvm-project/pull/150597.diff 4 Files Affected:
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index d4a34555ed820..b66896c4db5e6 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -806,7 +806,17 @@ void TargetLoweringBase::initActions() {
ISD::SDIVFIX, ISD::SDIVFIXSAT,
ISD::UDIVFIX, ISD::UDIVFIXSAT,
ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT,
- ISD::IS_FPCLASS},
+ ISD::IS_FPCLASS, ISD::FCBRT,
+ ISD::FLOG, ISD::FLOG2,
+ ISD::FLOG10, ISD::FEXP,
+ ISD::FEXP2, ISD::FEXP10,
+ ISD::FFLOOR, ISD::FNEARBYINT,
+ ISD::FCEIL, ISD::FRINT,
+ ISD::FTRUNC, ISD::FROUNDEVEN,
+ ISD::FTAN, ISD::FACOS,
+ ISD::FASIN, ISD::FATAN,
+ ISD::FCOSH, ISD::FSINH,
+ ISD::FTANH, ISD::FATAN2},
VT, Expand);
// Overflow operations default to expand
@@ -856,8 +866,7 @@ void TargetLoweringBase::initActions() {
{ISD::FCOPYSIGN, ISD::SIGN_EXTEND_INREG, ISD::ANY_EXTEND_VECTOR_INREG,
ISD::SIGN_EXTEND_VECTOR_INREG, ISD::ZERO_EXTEND_VECTOR_INREG,
ISD::SPLAT_VECTOR, ISD::LRINT, ISD::LLRINT, ISD::LROUND,
- ISD::LLROUND, ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN,
- ISD::FCOSH, ISD::FSINH, ISD::FTANH, ISD::FATAN2},
+ ISD::LLROUND},
VT, Expand);
// Constrained floating-point operations default to expand.
@@ -914,15 +923,6 @@ void TargetLoweringBase::initActions() {
{MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
Expand);
- // These library functions default to expand.
- setOperationAction({ISD::FCBRT, ISD::FLOG, ISD::FLOG2, ISD::FLOG10,
- ISD::FEXP, ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR,
- ISD::FNEARBYINT, ISD::FCEIL, ISD::FRINT, ISD::FTRUNC,
- ISD::FROUNDEVEN, ISD::FTAN, ISD::FACOS, ISD::FASIN,
- ISD::FATAN, ISD::FCOSH, ISD::FSINH, ISD::FTANH,
- ISD::FATAN2},
- {MVT::f32, MVT::f64, MVT::f128}, Expand);
-
// Insert custom handling default for llvm.canonicalize.*.
setOperationAction(ISD::FCANONICALIZE,
{MVT::f16, MVT::f32, MVT::f64, MVT::f128}, Expand);
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index e3ca09e512b3b..f25ce8723a2dc 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -391,8 +391,9 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
// Library functions. These default to Expand, but we have instructions
// for them.
setOperationAction({ISD::FCEIL, ISD::FPOW, ISD::FABS, ISD::FFLOOR,
- ISD::FROUNDEVEN, ISD::FTRUNC, ISD::FMINNUM, ISD::FMAXNUM},
- MVT::f32, Legal);
+ ISD::FROUNDEVEN, ISD::FTRUNC},
+ {MVT::f16, MVT::f32}, Legal);
+ setOperationAction({ISD::FMINNUM, ISD::FMAXNUM}, MVT::f32, Legal);
setOperationAction(ISD::FLOG2, MVT::f32, Custom);
setOperationAction(ISD::FROUND, {MVT::f32, MVT::f64}, Custom);
@@ -412,9 +413,10 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
setOperationAction(ISD::FREM, {MVT::f16, MVT::f32, MVT::f64}, Custom);
- if (Subtarget->has16BitInsts())
+ if (Subtarget->has16BitInsts()) {
setOperationAction(ISD::IS_FPCLASS, {MVT::f16, MVT::f32, MVT::f64}, Legal);
- else {
+ setOperationAction({ISD::FLOG2, ISD::FEXP2}, MVT::f16, Legal);
+ } else {
setOperationAction(ISD::IS_FPCLASS, {MVT::f32, MVT::f64}, Legal);
setOperationAction({ISD::FLOG2, ISD::FEXP2}, MVT::f16, Custom);
}
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index fca5dff092306..066b392213fa9 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -370,6 +370,11 @@ void ARMTargetLowering::addMVEVectorTypes(bool HasMVEFP) {
setOperationAction(ISD::FMINNUM, VT, Legal);
setOperationAction(ISD::FMAXNUM, VT, Legal);
setOperationAction(ISD::FROUND, VT, Legal);
+ setOperationAction(ISD::FROUNDEVEN, VT, Legal);
+ setOperationAction(ISD::FRINT, VT, Legal);
+ setOperationAction(ISD::FTRUNC, VT, Legal);
+ setOperationAction(ISD::FFLOOR, VT, Legal);
+ setOperationAction(ISD::FCEIL, VT, Legal);
setOperationAction(ISD::VECREDUCE_FADD, VT, Custom);
setOperationAction(ISD::VECREDUCE_FMUL, VT, Custom);
setOperationAction(ISD::VECREDUCE_FMIN, VT, Custom);
@@ -1507,6 +1512,12 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM_,
setOperationAction(ISD::FLOG2, MVT::f16, Promote);
setOperationAction(ISD::FROUND, MVT::f16, Legal);
+ setOperationAction(ISD::FROUNDEVEN, MVT::f16, Legal);
+ setOperationAction(ISD::FTRUNC, MVT::f16, Legal);
+ setOperationAction(ISD::FNEARBYINT, MVT::f16, Legal);
+ setOperationAction(ISD::FRINT, MVT::f16, Legal);
+ setOperationAction(ISD::FFLOOR, MVT::f16, Legal);
+ setOperationAction(ISD::FCEIL, MVT::f16, Legal);
}
if (Subtarget->hasNEON()) {
diff --git a/llvm/test/CodeGen/PowerPC/froundeven-legalization.ll b/llvm/test/CodeGen/PowerPC/froundeven-legalization.ll
new file mode 100644
index 0000000000000..cfa3a42cf378d
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/froundeven-legalization.ll
@@ -0,0 +1,125 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=powerpc64le < %s | FileCheck %s
+
+define void @test(ptr %p1, ptr %p2) {
+; CHECK-LABEL: test:
+; CHECK: # %bb.0:
+; CHECK-NEXT: mflr 0
+; CHECK-NEXT: stdu 1, -224(1)
+; CHECK-NEXT: std 0, 240(1)
+; CHECK-NEXT: .cfi_def_cfa_offset 224
+; CHECK-NEXT: .cfi_offset lr, 16
+; CHECK-NEXT: .cfi_offset r27, -40
+; CHECK-NEXT: .cfi_offset r28, -32
+; CHECK-NEXT: .cfi_offset r29, -24
+; CHECK-NEXT: .cfi_offset r30, -16
+; CHECK-NEXT: .cfi_offset v24, -176
+; CHECK-NEXT: .cfi_offset v25, -160
+; CHECK-NEXT: .cfi_offset v26, -144
+; CHECK-NEXT: .cfi_offset v27, -128
+; CHECK-NEXT: .cfi_offset v28, -112
+; CHECK-NEXT: .cfi_offset v29, -96
+; CHECK-NEXT: .cfi_offset v30, -80
+; CHECK-NEXT: .cfi_offset v31, -64
+; CHECK-NEXT: li 5, 48
+; CHECK-NEXT: std 27, 184(1) # 8-byte Folded Spill
+; CHECK-NEXT: li 27, 16
+; CHECK-NEXT: std 28, 192(1) # 8-byte Folded Spill
+; CHECK-NEXT: std 29, 200(1) # 8-byte Folded Spill
+; CHECK-NEXT: li 29, 32
+; CHECK-NEXT: li 28, 48
+; CHECK-NEXT: std 30, 208(1) # 8-byte Folded Spill
+; CHECK-NEXT: stvx 24, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 64
+; CHECK-NEXT: mr 30, 4
+; CHECK-NEXT: stvx 25, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 80
+; CHECK-NEXT: stvx 26, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 96
+; CHECK-NEXT: lxvd2x 58, 0, 3
+; CHECK-NEXT: stvx 27, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 112
+; CHECK-NEXT: lxvd2x 59, 3, 27
+; CHECK-NEXT: stvx 28, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 128
+; CHECK-NEXT: stvx 29, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 144
+; CHECK-NEXT: stvx 30, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: li 5, 160
+; CHECK-NEXT: lxvd2x 62, 3, 28
+; CHECK-NEXT: stvx 31, 1, 5 # 16-byte Folded Spill
+; CHECK-NEXT: lxvd2x 63, 3, 29
+; CHECK-NEXT: xxswapd 57, 58
+; CHECK-NEXT: xxswapd 1, 59
+; CHECK-NEXT: xxswapd 60, 62
+; CHECK-NEXT: xxswapd 61, 63
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 56, 1
+; CHECK-NEXT: xxlor 1, 59, 59
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 0, 1
+; CHECK-NEXT: xxlor 1, 60, 60
+; CHECK-NEXT: xxmrgld 59, 0, 56
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 60, 1
+; CHECK-NEXT: xxlor 1, 62, 62
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 0, 1
+; CHECK-NEXT: xxlor 1, 61, 61
+; CHECK-NEXT: xxmrgld 62, 0, 60
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 61, 1
+; CHECK-NEXT: xxlor 1, 63, 63
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 0, 1
+; CHECK-NEXT: xxlor 1, 57, 57
+; CHECK-NEXT: xxmrgld 63, 0, 61
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: xxswapd 61, 1
+; CHECK-NEXT: xxlor 1, 58, 58
+; CHECK-NEXT: bl roundeven
+; CHECK-NEXT: nop
+; CHECK-NEXT: li 3, 160
+; CHECK-NEXT: stxvd2x 63, 30, 29
+; CHECK-NEXT: xxswapd 0, 1
+; CHECK-NEXT: stxvd2x 62, 30, 28
+; CHECK-NEXT: stxvd2x 59, 30, 27
+; CHECK-NEXT: ld 29, 200(1) # 8-byte Folded Reload
+; CHECK-NEXT: ld 28, 192(1) # 8-byte Folded Reload
+; CHECK-NEXT: ld 27, 184(1) # 8-byte Folded Reload
+; CHECK-NEXT: lvx 31, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 144
+; CHECK-NEXT: xxmrgld 0, 0, 61
+; CHECK-NEXT: lvx 30, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 128
+; CHECK-NEXT: stxvd2x 0, 0, 30
+; CHECK-NEXT: ld 30, 208(1) # 8-byte Folded Reload
+; CHECK-NEXT: lvx 29, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 112
+; CHECK-NEXT: lvx 28, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 96
+; CHECK-NEXT: lvx 27, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 80
+; CHECK-NEXT: lvx 26, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 64
+; CHECK-NEXT: lvx 25, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: li 3, 48
+; CHECK-NEXT: lvx 24, 1, 3 # 16-byte Folded Reload
+; CHECK-NEXT: addi 1, 1, 224
+; CHECK-NEXT: ld 0, 16(1)
+; CHECK-NEXT: mtlr 0
+; CHECK-NEXT: blr
+ %v = load <8 x double>, ptr %p1, align 64
+ %res = call <8 x double> @llvm.roundeven.v8f64(<8 x double> %v)
+ store <8 x double> %res, ptr %p2, align 64
+ ret void
+}
+
+declare <8 x double> @llvm.roundeven.v8f64(<8 x double>)
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arsenm
approved these changes
Jul 25, 2025
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✅ With the latest revision this PR passed the C/C++ code formatter. |
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/cherry-pick fe0dbe0 |
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/pull-request #150970 |
tru
pushed a commit
to llvmbot/llvm-project
that referenced
this pull request
Jul 29, 2025
These float operations were expanded for scalar f32/f64/f128, but not for f16 and more problematically, not for vectors. A small subset of them was separately set to expand for vectors. Change these to always expand by default, and adjust targets to mark these as legal where necessary instead. This is a much safer default, and avoids unnecessary legalization failures because a target failed to manually mark them as expand. Fixes llvm#110753. Fixes llvm#121390. (cherry picked from commit fe0dbe0)
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These float operations were expanded for scalar f32/f64/f128, but not for f16 and more problematically, not for vectors. A small subset of them was separately set to expand for vectors.
Change these to always expand by default, and adjust targets to mark these as legal where necessary instead.
This is a much safer default, and avoids unnecessary legalization failures because a target failed to manually mark them as expand.
Fixes #110753.
Fixes #121390.