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[x86] lower calls to fmax and llvm.maxnum.* using maxps/maxpd (PR24475)
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rotateright committed Dec 28, 2015
1 parent 3c58c82 commit 9da2b64
Showing 2 changed files with 97 additions and 26 deletions.
6 changes: 4 additions & 2 deletions llvm/lib/Target/X86/X86ISelLowering.cpp
Original file line number Diff line number Diff line change
@@ -26926,10 +26926,12 @@ static SDValue performFMaxNumCombine(SDNode *N, SelectionDAG &DAG,
// should be able to lower to FMAX/FMIN alone.
// TODO: If an operand is already known to be a NaN or not a NaN, this
// should be an optional swap and FMAX/FMIN.
// TODO: Allow f64, vectors, and fminnum.
// TODO: Allow fminnum.

EVT VT = N->getValueType(0);
if (!(Subtarget->hasSSE1() && (VT == MVT::f32 || VT == MVT::v4f32)))
if (!((Subtarget->hasSSE1() && (VT == MVT::f32 || VT == MVT::v4f32)) ||
(Subtarget->hasSSE2() && (VT == MVT::f64 || VT == MVT::v2f64)) ||
(Subtarget->hasAVX() && (VT == MVT::v8f32 || VT == MVT::v4f64))))
return SDValue();

// This takes at least 3 instructions, so favor a library call when operating
117 changes: 93 additions & 24 deletions llvm/test/CodeGen/X86/fmaxnum.ll
Original file line number Diff line number Diff line change
@@ -14,6 +14,7 @@ declare <2 x double> @llvm.maxnum.v2f64(<2 x double>, <2 x double>)
declare <4 x double> @llvm.maxnum.v4f64(<4 x double>, <4 x double>)
declare <8 x double> @llvm.maxnum.v8f64(<8 x double>, <8 x double>)

; FIXME: As the vector tests show, the SSE run shouldn't need this many moves.

; CHECK-LABEL: @test_fmaxf
; SSE: movaps %xmm0, %xmm2
@@ -42,10 +43,23 @@ define float @test_fmaxf_minsize(float %x, float %y) minsize {
ret float %z
}

; FIXME: Doubles should be inlined similarly to floats.
; FIXME: As the vector tests show, the SSE run shouldn't need this many moves.

; CHECK-LABEL: @test_fmax
; CHECK: jmp fmax
; SSE: movapd %xmm0, %xmm2
; SSE-NEXT: cmpunordsd %xmm2, %xmm2
; SSE-NEXT: movapd %xmm2, %xmm3
; SSE-NEXT: andpd %xmm1, %xmm3
; SSE-NEXT: maxsd %xmm0, %xmm1
; SSE-NEXT: andnpd %xmm1, %xmm2
; SSE-NEXT: orpd %xmm3, %xmm2
; SSE-NEXT: movapd %xmm2, %xmm0
; SSE-NEXT: retq
;
; AVX: vmaxsd %xmm0, %xmm1, %xmm2
; AVX-NEXT: vcmpunordsd %xmm0, %xmm0, %xmm0
; AVX-NEXT: vblendvpd %xmm0, %xmm1, %xmm2, %xmm0
; AVX-NEXT: retq
define double @test_fmax(double %x, double %y) {
%z = call double @fmax(double %x, double %y) readnone
ret double %z
@@ -78,10 +92,22 @@ define float @test_intrinsic_fmaxf(float %x, float %y) {
ret float %z
}

; FIXME: Doubles should be inlined similarly to floats.

; CHECK-LABEL: @test_intrinsic_fmax
; CHECK: jmp fmax
; SSE: movapd %xmm0, %xmm2
; SSE-NEXT: cmpunordsd %xmm2, %xmm2
; SSE-NEXT: movapd %xmm2, %xmm3
; SSE-NEXT: andpd %xmm1, %xmm3
; SSE-NEXT: maxsd %xmm0, %xmm1
; SSE-NEXT: andnpd %xmm1, %xmm2
; SSE-NEXT: orpd %xmm3, %xmm2
; SSE-NEXT: movapd %xmm2, %xmm0
; SSE-NEXT: retq
;
; AVX: vmaxsd %xmm0, %xmm1, %xmm2
; AVX-NEXT: vcmpunordsd %xmm0, %xmm0, %xmm0
; AVX-NEXT: vblendvpd %xmm0, %xmm1, %xmm2, %xmm0
; AVX-NEXT: retq
define double @test_intrinsic_fmax(double %x, double %y) {
%z = call double @llvm.maxnum.f64(double %x, double %y) readnone
ret double %z
@@ -130,39 +156,82 @@ define <4 x float> @test_intrinsic_fmax_v4f32(<4 x float> %x, <4 x float> %y) {
ret <4 x float> %z
}

; FIXME: Vector of doubles should be inlined similarly to vector of floats.

; CHECK-LABEL: @test_intrinsic_fmax_v2f64
; CHECK: callq fmax
; CHECK: callq fmax
; SSE: movapd %xmm1, %xmm2
; SSE-NEXT: maxpd %xmm0, %xmm2
; SSE-NEXT: cmpunordpd %xmm0, %xmm0
; SSE-NEXT: andpd %xmm0, %xmm1
; SSE-NEXT: andnpd %xmm2, %xmm0
; SSE-NEXT: orpd %xmm1, %xmm0
; SSE-NEXT: retq
;
; AVX: vmaxpd %xmm0, %xmm1, %xmm2
; AVX-NEXT: vcmpunordpd %xmm0, %xmm0, %xmm0
; AVX-NEXT: vblendvpd %xmm0, %xmm1, %xmm2, %xmm0
; AVX-NEXT: retq
define <2 x double> @test_intrinsic_fmax_v2f64(<2 x double> %x, <2 x double> %y) {
%z = call <2 x double> @llvm.maxnum.v2f64(<2 x double> %x, <2 x double> %y) readnone
ret <2 x double> %z
}

; FIXME: Vector of doubles should be inlined similarly to vector of floats.

; CHECK-LABEL: @test_intrinsic_fmax_v4f64
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; SSE: movapd %xmm2, %xmm4
; SSE-NEXT: maxpd %xmm0, %xmm4
; SSE-NEXT: cmpunordpd %xmm0, %xmm0
; SSE-NEXT: andpd %xmm0, %xmm2
; SSE-NEXT: andnpd %xmm4, %xmm0
; SSE-NEXT: orpd %xmm2, %xmm0
; SSE-NEXT: movapd %xmm3, %xmm2
; SSE-NEXT: maxpd %xmm1, %xmm2
; SSE-NEXT: cmpunordpd %xmm1, %xmm1
; SSE-NEXT: andpd %xmm1, %xmm3
; SSE-NEXT: andnpd %xmm2, %xmm1
; SSE-NEXT: orpd %xmm3, %xmm1
; SSE-NEXT: retq
;
; AVX: vmaxpd %ymm0, %ymm1, %ymm2
; AVX-NEXT: vcmpunordpd %ymm0, %ymm0, %ymm0
; AVX-NEXT: vblendvpd %ymm0, %ymm1, %ymm2, %ymm0
; AVX-NEXT: retq
define <4 x double> @test_intrinsic_fmax_v4f64(<4 x double> %x, <4 x double> %y) {
%z = call <4 x double> @llvm.maxnum.v4f64(<4 x double> %x, <4 x double> %y) readnone
ret <4 x double> %z
}

; FIXME: Vector of doubles should be inlined similarly to vector of floats.

; CHECK-LABEL: @test_intrinsic_fmax_v8f64
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; CHECK: callq fmax
; SSE: movapd %xmm4, %xmm8
; SSE-NEXT: maxpd %xmm0, %xmm8
; SSE-NEXT: cmpunordpd %xmm0, %xmm0
; SSE-NEXT: andpd %xmm0, %xmm4
; SSE-NEXT: andnpd %xmm8, %xmm0
; SSE-NEXT: orpd %xmm4, %xmm0
; SSE-NEXT: movapd %xmm5, %xmm4
; SSE-NEXT: maxpd %xmm1, %xmm4
; SSE-NEXT: cmpunordpd %xmm1, %xmm1
; SSE-NEXT: andpd %xmm1, %xmm5
; SSE-NEXT: andnpd %xmm4, %xmm1
; SSE-NEXT: orpd %xmm5, %xmm1
; SSE-NEXT: movapd %xmm6, %xmm4
; SSE-NEXT: maxpd %xmm2, %xmm4
; SSE-NEXT: cmpunordpd %xmm2, %xmm2
; SSE-NEXT: andpd %xmm2, %xmm6
; SSE-NEXT: andnpd %xmm4, %xmm2
; SSE-NEXT: orpd %xmm6, %xmm2
; SSE-NEXT: movapd %xmm7, %xmm4
; SSE-NEXT: maxpd %xmm3, %xmm4
; SSE-NEXT: cmpunordpd %xmm3, %xmm3
; SSE-NEXT: andpd %xmm3, %xmm7
; SSE-NEXT: andnpd %xmm4, %xmm3
; SSE-NEXT: orpd %xmm7, %xmm3
; SSE-NEXT: retq
;
; AVX: vmaxpd %ymm0, %ymm2, %ymm4
; AVX-NEXT: vcmpunordpd %ymm0, %ymm0, %ymm0
; AVX-NEXT: vblendvpd %ymm0, %ymm2, %ymm4, %ymm0
; AVX-NEXT: vmaxpd %ymm1, %ymm3, %ymm2
; AVX-NEXT: vcmpunordpd %ymm1, %ymm1, %ymm1
; AVX-NEXT: vblendvpd %ymm1, %ymm3, %ymm2, %ymm1
; AVX-NEXT: retq
define <8 x double> @test_intrinsic_fmax_v8f64(<8 x double> %x, <8 x double> %y) {
%z = call <8 x double> @llvm.maxnum.v8f64(<8 x double> %x, <8 x double> %y) readnone
ret <8 x double> %z

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