[llvm-branch-commits] [llvm] DAG: Lower single infinity is.fpclass tests to fcmp (PR #100380)
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llvm-branch-commits at lists.llvm.org
Wed Jul 24 06:58:47 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-x86
Author: Matt Arsenault (arsenm)
<details>
<summary>Changes</summary>
InstCombine also should have taken care of this, but this
should be helpful when the fcmp based lowering strategy tries
to combine multiple tests.
---
Full diff: https://github.com/llvm/llvm-project/pull/100380.diff
4 Files Affected:
- (modified) llvm/lib/CodeGen/CodeGenCommonISel.cpp (+2)
- (modified) llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp (+28-7)
- (modified) llvm/test/CodeGen/X86/is_fpclass-fp80.ll (+26-26)
- (modified) llvm/test/CodeGen/X86/is_fpclass.ll (+66-71)
``````````diff
diff --git a/llvm/lib/CodeGen/CodeGenCommonISel.cpp b/llvm/lib/CodeGen/CodeGenCommonISel.cpp
index f5207d8b9d124..bb09b0d1140fc 100644
--- a/llvm/lib/CodeGen/CodeGenCommonISel.cpp
+++ b/llvm/lib/CodeGen/CodeGenCommonISel.cpp
@@ -202,6 +202,8 @@ FPClassTest llvm::invertFPClassTestIfSimpler(FPClassTest Test, bool UseFP) {
case fcSubnormal | fcZero | fcNan:
return InvertedTest;
case fcInf | fcNan:
+ case fcPosInf | fcNan:
+ case fcNegInf | fcNan:
// If we're trying to use fcmp, we can take advantage of the nan check
// behavior of the compare (but this is more instructions in the integer
// expansion).
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ba7c89a33f604..0036c182ab9db 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -8599,6 +8599,16 @@ SDValue TargetLowering::expandIS_FPCLASS(EVT ResultVT, SDValue Op,
ISD::CondCode OrderedCmpOpcode = IsInvertedFP ? ISD::SETUNE : ISD::SETOEQ;
ISD::CondCode UnorderedCmpOpcode = IsInvertedFP ? ISD::SETONE : ISD::SETUEQ;
+ // See if we can fold an | fcNan into an unordered compare.
+ FPClassTest OrderedFPTestMask = FPTestMask & ~fcNan;
+
+ // Can't fold the ordered check if we're only testing for snan or qnan
+ // individually.
+ if ((FPTestMask & fcNan) != fcNan)
+ OrderedFPTestMask = FPTestMask;
+
+ const bool IsOrdered = FPTestMask == OrderedFPTestMask;
+
if (std::optional<bool> IsCmp0 =
isFCmpEqualZero(FPTestMask, Semantics, DAG.getMachineFunction());
IsCmp0 && (isCondCodeLegalOrCustom(
@@ -8618,18 +8628,29 @@ SDValue TargetLowering::expandIS_FPCLASS(EVT ResultVT, SDValue Op,
return DAG.getSetCC(DL, ResultVT, Op, Op,
IsInvertedFP ? ISD::SETO : ISD::SETUO);
- bool IsOrderedInf = FPTestMask == fcInf;
- if ((FPTestMask == fcInf || FPTestMask == (fcInf | fcNan)) &&
- isCondCodeLegalOrCustom(IsOrderedInf ? OrderedCmpOpcode
- : UnorderedCmpOpcode,
- OperandVT.getScalarType().getSimpleVT()) &&
- isOperationLegalOrCustom(ISD::FABS, OperandVT.getScalarType())) {
+ if (OrderedFPTestMask == fcInf &&
+ isCondCodeLegalOrCustom(IsOrdered ? OrderedCmpOpcode
+ : UnorderedCmpOpcode,
+ OperandVT.getScalarType().getSimpleVT())) {
// isinf(x) --> fabs(x) == inf
SDValue Abs = DAG.getNode(ISD::FABS, DL, OperandVT, Op);
SDValue Inf =
DAG.getConstantFP(APFloat::getInf(Semantics), DL, OperandVT);
return DAG.getSetCC(DL, ResultVT, Abs, Inf,
- IsOrderedInf ? OrderedCmpOpcode : UnorderedCmpOpcode);
+ IsOrdered ? OrderedCmpOpcode : UnorderedCmpOpcode);
+ }
+
+ if (OrderedFPTestMask == fcPosInf || OrderedFPTestMask == fcNegInf) {
+ // isposinf(x) --> x == inf
+ // isneginf(x) --> x == -inf
+ // isposinf(x) || nan --> x u== inf
+ // isneginf(x) || nan --> x u== -inf
+
+ SDValue Inf = DAG.getConstantFP(
+ APFloat::getInf(Semantics, OrderedFPTestMask == fcNegInf), DL,
+ OperandVT);
+ return DAG.getSetCC(DL, ResultVT, Op, Inf,
+ IsOrdered ? OrderedCmpOpcode : UnorderedCmpOpcode);
}
}
diff --git a/llvm/test/CodeGen/X86/is_fpclass-fp80.ll b/llvm/test/CodeGen/X86/is_fpclass-fp80.ll
index 52d294ca01720..56d3ba7cd7b2b 100644
--- a/llvm/test/CodeGen/X86/is_fpclass-fp80.ll
+++ b/llvm/test/CodeGen/X86/is_fpclass-fp80.ll
@@ -265,23 +265,24 @@ entry:
define i1 @is_posinf_f80(x86_fp80 %x) nounwind {
; X86-LABEL: is_posinf_f80:
; X86: # %bb.0: # %entry
-; X86-NEXT: movzwl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: movl $-2147483648, %ecx # imm = 0x80000000
-; X86-NEXT: xorl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT: xorl $32767, %eax # imm = 0x7FFF
-; X86-NEXT: orl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: orl %ecx, %eax
-; X86-NEXT: sete %al
+; X86-NEXT: fldt {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fxch %st(1)
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setae %al
; X86-NEXT: retl
;
; X64-LABEL: is_posinf_f80:
; X64: # %bb.0: # %entry
-; X64-NEXT: movzwl {{[0-9]+}}(%rsp), %eax
-; X64-NEXT: movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; X64-NEXT: xorq {{[0-9]+}}(%rsp), %rcx
-; X64-NEXT: xorq $32767, %rax # imm = 0x7FFF
-; X64-NEXT: orq %rcx, %rax
-; X64-NEXT: sete %al
+; X64-NEXT: fldt {{[0-9]+}}(%rsp)
+; X64-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}(%rip)
+; X64-NEXT: fxch %st(1)
+; X64-NEXT: fucompi %st(1), %st
+; X64-NEXT: fstp %st(0)
+; X64-NEXT: setae %al
; X64-NEXT: retq
entry:
%0 = tail call i1 @llvm.is.fpclass.f80(x86_fp80 %x, i32 512) ; 0x200 = "+inf"
@@ -291,23 +292,22 @@ entry:
define i1 @is_neginf_f80(x86_fp80 %x) nounwind {
; X86-LABEL: is_neginf_f80:
; X86: # %bb.0: # %entry
-; X86-NEXT: movzwl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: xorl $65535, %eax # imm = 0xFFFF
-; X86-NEXT: movl $-2147483648, %ecx # imm = 0x80000000
-; X86-NEXT: xorl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT: orl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: orl %ecx, %eax
-; X86-NEXT: sete %al
+; X86-NEXT: fldt {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setae %al
; X86-NEXT: retl
;
; X64-LABEL: is_neginf_f80:
; X64: # %bb.0: # %entry
-; X64-NEXT: movzwl {{[0-9]+}}(%rsp), %eax
-; X64-NEXT: xorq $65535, %rax # imm = 0xFFFF
-; X64-NEXT: movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; X64-NEXT: xorq {{[0-9]+}}(%rsp), %rcx
-; X64-NEXT: orq %rax, %rcx
-; X64-NEXT: sete %al
+; X64-NEXT: fldt {{[0-9]+}}(%rsp)
+; X64-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}(%rip)
+; X64-NEXT: fucompi %st(1), %st
+; X64-NEXT: fstp %st(0)
+; X64-NEXT: setae %al
; X64-NEXT: retq
entry:
%0 = tail call i1 @llvm.is.fpclass.f80(x86_fp80 %x, i32 4) ; "-inf"
diff --git a/llvm/test/CodeGen/X86/is_fpclass.ll b/llvm/test/CodeGen/X86/is_fpclass.ll
index 86cee3d2c8e69..ba7d13aca03d1 100644
--- a/llvm/test/CodeGen/X86/is_fpclass.ll
+++ b/llvm/test/CodeGen/X86/is_fpclass.ll
@@ -186,15 +186,20 @@ entry:
define i1 @is_plus_inf_f(float %x) {
; X86-LABEL: is_plus_inf_f:
; X86: # %bb.0: # %entry
-; X86-NEXT: cmpl $2139095040, {{[0-9]+}}(%esp) # imm = 0x7F800000
-; X86-NEXT: sete %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fxch %st(1)
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setae %al
; X86-NEXT: retl
;
; X64-LABEL: is_plus_inf_f:
; X64: # %bb.0: # %entry
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X64-NEXT: sete %al
+; X64-NEXT: ucomiss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT: setae %al
; X64-NEXT: retq
entry:
%0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 512) ; 0x200 = "+inf"
@@ -204,15 +209,20 @@ entry:
define i1 @is_minus_inf_f(float %x) {
; X86-LABEL: is_minus_inf_f:
; X86: # %bb.0: # %entry
-; X86-NEXT: cmpl $-8388608, {{[0-9]+}}(%esp) # imm = 0xFF800000
-; X86-NEXT: sete %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setae %al
; X86-NEXT: retl
;
; X64-LABEL: is_minus_inf_f:
; X64: # %bb.0: # %entry
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X64-NEXT: sete %al
+; X64-NEXT: movss {{.*#+}} xmm1 = [-Inf,0.0E+0,0.0E+0,0.0E+0]
+; X64-NEXT: ucomiss %xmm0, %xmm1
+; X64-NEXT: setae %al
; X64-NEXT: retq
entry:
%0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 4) ; "-inf"
@@ -222,15 +232,20 @@ entry:
define i1 @not_is_minus_inf_f(float %x) {
; X86-LABEL: not_is_minus_inf_f:
; X86: # %bb.0: # %entry
-; X86-NEXT: cmpl $-8388608, {{[0-9]+}}(%esp) # imm = 0xFF800000
-; X86-NEXT: setne %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setb %al
; X86-NEXT: retl
;
; X64-LABEL: not_is_minus_inf_f:
; X64: # %bb.0: # %entry
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X64-NEXT: setne %al
+; X64-NEXT: movss {{.*#+}} xmm1 = [-Inf,0.0E+0,0.0E+0,0.0E+0]
+; X64-NEXT: ucomiss %xmm0, %xmm1
+; X64-NEXT: setb %al
; X64-NEXT: retq
entry:
%0 = tail call i1 @llvm.is.fpclass.f32(float %x, i32 1019) ; ~"-inf"
@@ -2116,24 +2131,19 @@ entry:
define i1 @is_plus_inf_or_nan_f(float %x) {
; X86-LABEL: is_plus_inf_or_nan_f:
; X86: # %bb.0:
-; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X86-NEXT: sete %cl
-; X86-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X86-NEXT: cmpl $2139095041, %eax # imm = 0x7F800001
-; X86-NEXT: setge %al
-; X86-NEXT: orb %cl, %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: sete %al
; X86-NEXT: retl
;
; X64-LABEL: is_plus_inf_or_nan_f:
; X64: # %bb.0:
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X64-NEXT: sete %cl
-; X64-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X64-NEXT: cmpl $2139095041, %eax # imm = 0x7F800001
-; X64-NEXT: setge %al
-; X64-NEXT: orb %cl, %al
+; X64-NEXT: ucomiss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT: sete %al
; X64-NEXT: retq
%class = tail call i1 @llvm.is.fpclass.f32(float %x, i32 515) ; 0x200|0x3 = "+inf|nan"
ret i1 %class
@@ -2142,24 +2152,19 @@ define i1 @is_plus_inf_or_nan_f(float %x) {
define i1 @is_minus_inf_or_nan_f(float %x) {
; X86-LABEL: is_minus_inf_or_nan_f:
; X86: # %bb.0:
-; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X86-NEXT: sete %cl
-; X86-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X86-NEXT: cmpl $2139095041, %eax # imm = 0x7F800001
-; X86-NEXT: setge %al
-; X86-NEXT: orb %cl, %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: sete %al
; X86-NEXT: retl
;
; X64-LABEL: is_minus_inf_or_nan_f:
; X64: # %bb.0:
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X64-NEXT: sete %cl
-; X64-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X64-NEXT: cmpl $2139095041, %eax # imm = 0x7F800001
-; X64-NEXT: setge %al
-; X64-NEXT: orb %cl, %al
+; X64-NEXT: ucomiss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT: sete %al
; X64-NEXT: retq
%class = tail call i1 @llvm.is.fpclass.f32(float %x, i32 7) ; "-inf|nan"
ret i1 %class
@@ -2168,24 +2173,19 @@ define i1 @is_minus_inf_or_nan_f(float %x) {
define i1 @not_is_plus_inf_or_nan_f(float %x) {
; X86-LABEL: not_is_plus_inf_or_nan_f:
; X86: # %bb.0:
-; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X86-NEXT: sete %cl
-; X86-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X86-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X86-NEXT: setl %al
-; X86-NEXT: orb %cl, %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setne %al
; X86-NEXT: retl
;
; X64-LABEL: not_is_plus_inf_or_nan_f:
; X64: # %bb.0:
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $-8388608, %eax # imm = 0xFF800000
-; X64-NEXT: sete %cl
-; X64-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X64-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X64-NEXT: setl %al
-; X64-NEXT: orb %cl, %al
+; X64-NEXT: ucomiss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT: setne %al
; X64-NEXT: retq
%class = tail call i1 @llvm.is.fpclass.f32(float %x, i32 508) ; ~(0x200|0x3) = "~(+inf|nan)"
ret i1 %class
@@ -2194,24 +2194,19 @@ define i1 @not_is_plus_inf_or_nan_f(float %x) {
define i1 @not_is_minus_inf_or_nan_f(float %x) {
; X86-LABEL: not_is_minus_inf_or_nan_f:
; X86: # %bb.0:
-; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X86-NEXT: sete %cl
-; X86-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X86-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X86-NEXT: setl %al
-; X86-NEXT: orb %cl, %al
+; X86-NEXT: flds {{[0-9]+}}(%esp)
+; X86-NEXT: flds {{\.?LCPI[0-9]+_[0-9]+}}
+; X86-NEXT: fucompp
+; X86-NEXT: fnstsw %ax
+; X86-NEXT: # kill: def $ah killed $ah killed $ax
+; X86-NEXT: sahf
+; X86-NEXT: setne %al
; X86-NEXT: retl
;
; X64-LABEL: not_is_minus_inf_or_nan_f:
; X64: # %bb.0:
-; X64-NEXT: movd %xmm0, %eax
-; X64-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X64-NEXT: sete %cl
-; X64-NEXT: andl $2147483647, %eax # imm = 0x7FFFFFFF
-; X64-NEXT: cmpl $2139095040, %eax # imm = 0x7F800000
-; X64-NEXT: setl %al
-; X64-NEXT: orb %cl, %al
+; X64-NEXT: ucomiss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT: setne %al
; X64-NEXT: retq
%class = tail call i1 @llvm.is.fpclass.f32(float %x, i32 1016) ; "~(-inf|nan)"
ret i1 %class
``````````
</details>
https://github.com/llvm/llvm-project/pull/100380
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