694 changes: 694 additions & 0 deletions llvm/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp
View file

Large diffs are not rendered by default.

4 changes: 4 additions & 0 deletions llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -204,6 +204,10 @@ bool AArch64PassConfig::addPostRegAlloc() {
// Change dead register definitions to refer to the zero register.
if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
addPass(createAArch64DeadRegisterDefinitions());
if (TM->getOptLevel() != CodeGenOpt::None &&
TM->getSubtarget<AArch64Subtarget>().isCortexA57())
// Improve performance for some FP/SIMD code for A57.
addPass(createAArch64A57FPLoadBalancing());
return true;
}

Expand Down
1 change: 1 addition & 0 deletions llvm/lib/Target/AArch64/CMakeLists.txt
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@ tablegen(LLVM AArch64GenDisassemblerTables.inc -gen-disassembler)
add_public_tablegen_target(AArch64CommonTableGen)

add_llvm_target(AArch64CodeGen
AArch64A57FPLoadBalancing.cpp
AArch64AddressTypePromotion.cpp
AArch64AdvSIMDScalarPass.cpp
AArch64AsmPrinter.cpp
Expand Down
323 changes: 323 additions & 0 deletions llvm/test/CodeGen/AArch64/aarch64-a57-fp-load-balancing.ll
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,323 @@
; RUN: llc < %s -mcpu=cortex-a57 -aarch64-a57-fp-load-balancing-override=1 -aarch64-a57-fp-load-balancing-force-all | FileCheck %s --check-prefix CHECK --check-prefix CHECK-EVEN
; RUN: llc < %s -mcpu=cortex-a57 -aarch64-a57-fp-load-balancing-override=2 -aarch64-a57-fp-load-balancing-force-all | FileCheck %s --check-prefix CHECK --check-prefix CHECK-ODD

; Test the AArch64A57FPLoadBalancing pass. This pass relies heavily on register allocation, so
; our test strategy is to:
; * Force the pass to always perform register swapping even if the dest register is of the
; correct color already (-force-all)
; * Force the pass to ignore all hints it obtained from regalloc (-deterministic-balance),
; and run it twice, once where it always hints odd, and once where it always hints even.
;
; We then use regex magic to check that in the two cases the register allocation is
; different; this is what gives us the testing coverage and distinguishes cases where
; the pass has done some work versus accidental regalloc.

target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
target triple = "aarch64"

; Non-overlapping groups - shouldn't need any changing at all.

; CHECK-LABEL: f1:
; CHECK-EVEN: fmadd [[x:d[0-9]*[02468]]]
; CHECK-ODD: fmadd [[x:d[0-9]*[13579]]]
; CHECK: fmadd [[x]]
; CHECK: fmsub [[x]]
; CHECK: fmadd [[x]]
; CHECK: str [[x]]

define void @f1(double* nocapture readonly %p, double* nocapture %q) #0 {
entry:
%0 = load double* %p, align 8
%arrayidx1 = getelementptr inbounds double* %p, i64 1
%1 = load double* %arrayidx1, align 8
%arrayidx2 = getelementptr inbounds double* %p, i64 2
%2 = load double* %arrayidx2, align 8
%arrayidx3 = getelementptr inbounds double* %p, i64 3
%3 = load double* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds double* %p, i64 4
%4 = load double* %arrayidx4, align 8
%mul = fmul fast double %0, %1
%add = fadd fast double %mul, %4
%mul5 = fmul fast double %1, %2
%add6 = fadd fast double %mul5, %add
%mul7 = fmul fast double %1, %3
%sub = fsub fast double %add6, %mul7
%mul8 = fmul fast double %2, %3
%add9 = fadd fast double %mul8, %sub
store double %add9, double* %q, align 8
%arrayidx11 = getelementptr inbounds double* %p, i64 5
%5 = load double* %arrayidx11, align 8
%arrayidx12 = getelementptr inbounds double* %p, i64 6
%6 = load double* %arrayidx12, align 8
%arrayidx13 = getelementptr inbounds double* %p, i64 7
%7 = load double* %arrayidx13, align 8
%mul15 = fmul fast double %6, %7
%mul16 = fmul fast double %0, %5
%add17 = fadd fast double %mul16, %mul15
%mul18 = fmul fast double %5, %6
%add19 = fadd fast double %mul18, %add17
%arrayidx20 = getelementptr inbounds double* %q, i64 1
store double %add19, double* %arrayidx20, align 8
ret void
}

; Overlapping groups - coloring needed.

; CHECK-LABEL: f2:
; CHECK-EVEN: fmadd [[x:d[0-9]*[02468]]]
; CHECK-EVEN: fmul [[y:d[0-9]*[13579]]]
; CHECK-ODD: fmadd [[x:d[0-9]*[13579]]]
; CHECK-ODD: fmul [[y:d[0-9]*[02468]]]
; CHECK: fmadd [[x]]
; CHECK: fmadd [[y]]
; CHECK: fmsub [[x]]
; CHECK: fmadd [[y]]
; CHECK: fmadd [[x]]
; CHECK: stp [[x]], [[y]]

define void @f2(double* nocapture readonly %p, double* nocapture %q) #0 {
entry:
%0 = load double* %p, align 8
%arrayidx1 = getelementptr inbounds double* %p, i64 1
%1 = load double* %arrayidx1, align 8
%arrayidx2 = getelementptr inbounds double* %p, i64 2
%2 = load double* %arrayidx2, align 8
%arrayidx3 = getelementptr inbounds double* %p, i64 3
%3 = load double* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds double* %p, i64 4
%4 = load double* %arrayidx4, align 8
%arrayidx5 = getelementptr inbounds double* %p, i64 5
%5 = load double* %arrayidx5, align 8
%arrayidx6 = getelementptr inbounds double* %p, i64 6
%6 = load double* %arrayidx6, align 8
%arrayidx7 = getelementptr inbounds double* %p, i64 7
%7 = load double* %arrayidx7, align 8
%mul = fmul fast double %0, %1
%add = fadd fast double %mul, %7
%mul8 = fmul fast double %5, %6
%mul9 = fmul fast double %1, %2
%add10 = fadd fast double %mul9, %add
%mul11 = fmul fast double %3, %4
%add12 = fadd fast double %mul11, %mul8
%mul13 = fmul fast double %1, %3
%sub = fsub fast double %add10, %mul13
%mul14 = fmul fast double %4, %5
%add15 = fadd fast double %mul14, %add12
%mul16 = fmul fast double %2, %3
%add17 = fadd fast double %mul16, %sub
store double %add17, double* %q, align 8
%arrayidx19 = getelementptr inbounds double* %q, i64 1
store double %add15, double* %arrayidx19, align 8
ret void
}

; Dest register is live on block exit - fixup needed.

; CHECK-LABEL: f3:
; CHECK-EVEN: fmadd [[x:d[0-9]*[02468]]]
; CHECK-ODD: fmadd [[x:d[0-9]*[13579]]]
; CHECK: fmadd [[x]]
; CHECK: fmsub [[x]]
; CHECK: fmadd [[y:d[0-9]+]], {{.*}}, [[x]]
; CHECK: str [[y]]

define void @f3(double* nocapture readonly %p, double* nocapture %q) #0 {
entry:
%0 = load double* %p, align 8
%arrayidx1 = getelementptr inbounds double* %p, i64 1
%1 = load double* %arrayidx1, align 8
%arrayidx2 = getelementptr inbounds double* %p, i64 2
%2 = load double* %arrayidx2, align 8
%arrayidx3 = getelementptr inbounds double* %p, i64 3
%3 = load double* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds double* %p, i64 4
%4 = load double* %arrayidx4, align 8
%mul = fmul fast double %0, %1
%add = fadd fast double %mul, %4
%mul5 = fmul fast double %1, %2
%add6 = fadd fast double %mul5, %add
%mul7 = fmul fast double %1, %3
%sub = fsub fast double %add6, %mul7
%mul8 = fmul fast double %2, %3
%add9 = fadd fast double %mul8, %sub
%cmp = fcmp oeq double %3, 0.000000e+00
br i1 %cmp, label %if.then, label %if.end

if.then: ; preds = %entry
tail call void bitcast (void (...)* @g to void ()*)() #2
br label %if.end

if.end: ; preds = %if.then, %entry
store double %add9, double* %q, align 8
ret void
}

declare void @g(...) #1

; Single precision version of f2.

; CHECK-LABEL: f4:
; CHECK-EVEN: fmadd [[x:s[0-9]*[02468]]]
; CHECK-EVEN: fmul [[y:s[0-9]*[13579]]]
; CHECK-ODD: fmadd [[x:s[0-9]*[13579]]]
; CHECK-ODD: fmul [[y:s[0-9]*[02468]]]
; CHECK: fmadd [[x]]
; CHECK: fmadd [[y]]
; CHECK: fmsub [[x]]
; CHECK: fmadd [[y]]
; CHECK: fmadd [[x]]
; CHECK: stp [[x]], [[y]]

define void @f4(float* nocapture readonly %p, float* nocapture %q) #0 {
entry:
%0 = load float* %p, align 4
%arrayidx1 = getelementptr inbounds float* %p, i64 1
%1 = load float* %arrayidx1, align 4
%arrayidx2 = getelementptr inbounds float* %p, i64 2
%2 = load float* %arrayidx2, align 4
%arrayidx3 = getelementptr inbounds float* %p, i64 3
%3 = load float* %arrayidx3, align 4
%arrayidx4 = getelementptr inbounds float* %p, i64 4
%4 = load float* %arrayidx4, align 4
%arrayidx5 = getelementptr inbounds float* %p, i64 5
%5 = load float* %arrayidx5, align 4
%arrayidx6 = getelementptr inbounds float* %p, i64 6
%6 = load float* %arrayidx6, align 4
%arrayidx7 = getelementptr inbounds float* %p, i64 7
%7 = load float* %arrayidx7, align 4
%mul = fmul fast float %0, %1
%add = fadd fast float %mul, %7
%mul8 = fmul fast float %5, %6
%mul9 = fmul fast float %1, %2
%add10 = fadd fast float %mul9, %add
%mul11 = fmul fast float %3, %4
%add12 = fadd fast float %mul11, %mul8
%mul13 = fmul fast float %1, %3
%sub = fsub fast float %add10, %mul13
%mul14 = fmul fast float %4, %5
%add15 = fadd fast float %mul14, %add12
%mul16 = fmul fast float %2, %3
%add17 = fadd fast float %mul16, %sub
store float %add17, float* %q, align 4
%arrayidx19 = getelementptr inbounds float* %q, i64 1
store float %add15, float* %arrayidx19, align 4
ret void
}

; Single precision version of f3

; CHECK-LABEL: f5:
; CHECK-EVEN: fmadd [[x:s[0-9]*[02468]]]
; CHECK-ODD: fmadd [[x:s[0-9]*[13579]]]
; CHECK: fmadd [[x]]
; CHECK: fmsub [[x]]
; CHECK: fmadd [[y:s[0-9]+]], {{.*}}, [[x]]
; CHECK: str [[y]]

define void @f5(float* nocapture readonly %p, float* nocapture %q) #0 {
entry:
%0 = load float* %p, align 4
%arrayidx1 = getelementptr inbounds float* %p, i64 1
%1 = load float* %arrayidx1, align 4
%arrayidx2 = getelementptr inbounds float* %p, i64 2
%2 = load float* %arrayidx2, align 4
%arrayidx3 = getelementptr inbounds float* %p, i64 3
%3 = load float* %arrayidx3, align 4
%arrayidx4 = getelementptr inbounds float* %p, i64 4
%4 = load float* %arrayidx4, align 4
%mul = fmul fast float %0, %1
%add = fadd fast float %mul, %4
%mul5 = fmul fast float %1, %2
%add6 = fadd fast float %mul5, %add
%mul7 = fmul fast float %1, %3
%sub = fsub fast float %add6, %mul7
%mul8 = fmul fast float %2, %3
%add9 = fadd fast float %mul8, %sub
%cmp = fcmp oeq float %3, 0.000000e+00
br i1 %cmp, label %if.then, label %if.end

if.then: ; preds = %entry
tail call void bitcast (void (...)* @g to void ()*)() #2
br label %if.end

if.end: ; preds = %if.then, %entry
store float %add9, float* %q, align 4
ret void
}

; Test that regmask clobbering stops a chain sequence.

; CHECK-LABEL: f6:
; CHECK-EVEN: fmadd [[x:d[0-9]*[02468]]]
; CHECK-ODD: fmadd [[x:d[0-9]*[13579]]]
; CHECK: fmadd [[x]]
; CHECK: fmsub [[x]]
; CHECK: fmadd d0, {{.*}}, [[x]]
; CHECK: bl hh
; CHECK: str d0

define void @f6(double* nocapture readonly %p, double* nocapture %q) #0 {
entry:
%0 = load double* %p, align 8
%arrayidx1 = getelementptr inbounds double* %p, i64 1
%1 = load double* %arrayidx1, align 8
%arrayidx2 = getelementptr inbounds double* %p, i64 2
%2 = load double* %arrayidx2, align 8
%arrayidx3 = getelementptr inbounds double* %p, i64 3
%3 = load double* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds double* %p, i64 4
%4 = load double* %arrayidx4, align 8
%mul = fmul fast double %0, %1
%add = fadd fast double %mul, %4
%mul5 = fmul fast double %1, %2
%add6 = fadd fast double %mul5, %add
%mul7 = fmul fast double %1, %3
%sub = fsub fast double %add6, %mul7
%mul8 = fmul fast double %2, %3
%add9 = fadd fast double %mul8, %sub
%call = tail call double @hh(double %add9) #2
store double %call, double* %q, align 8
ret void
}

declare double @hh(double) #1

; Check that we correctly deal with repeated operands.
; The following testcase creates:
; %D1<def> = FADDDrr %D0<kill>, %D0
; We'll get a crash if we naively look at the first operand, remove it
; from the substitution list then look at the second operand.

; CHECK: fmadd [[x:d[0-9]+]]
; CHECK: fadd d1, [[x]], [[x]]

define void @f7(double* nocapture readonly %p, double* nocapture %q) #0 {
entry:
%0 = load double* %p, align 8
%arrayidx1 = getelementptr inbounds double* %p, i64 1
%1 = load double* %arrayidx1, align 8
%arrayidx2 = getelementptr inbounds double* %p, i64 2
%2 = load double* %arrayidx2, align 8
%arrayidx3 = getelementptr inbounds double* %p, i64 3
%3 = load double* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds double* %p, i64 4
%4 = load double* %arrayidx4, align 8
%mul = fmul fast double %0, %1
%add = fadd fast double %mul, %4
%mul5 = fmul fast double %1, %2
%add6 = fadd fast double %mul5, %add
%mul7 = fmul fast double %1, %3
%sub = fsub fast double %add6, %mul7
%mul8 = fmul fast double %2, %3
%add9 = fadd fast double %mul8, %sub
%add10 = fadd fast double %add9, %add9
call void @hhh(double 0.0, double %add10)
ret void
}

declare void @hhh(double, double)

attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="true" "use-soft-float"="false" }
attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="true" "use-soft-float"="false" }
attributes #2 = { nounwind }