[PATCH] D67363: [BreakFalseDeps] ignore function with minsize attribute

[Sanjay Patel via Phabricator via llvm-commits]

spatel updated this revision to Diff 219546.
spatel added a comment.

Patch updated:
Rebased with improved test coverage for ARM and x86:
rL371526 <https://reviews.llvm.org/rL371526>
rL371525 <https://reviews.llvm.org/rL371525>


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67363/new/

https://reviews.llvm.org/D67363

Files:
  llvm/lib/CodeGen/BreakFalseDeps.cpp
  llvm/test/CodeGen/ARM/a15-partial-update.ll
  llvm/test/CodeGen/X86/sqrt-partial.ll
  llvm/test/CodeGen/X86/stack-folding-fp-sse42.ll


Index: llvm/test/CodeGen/X86/stack-folding-fp-sse42.ll
===================================================================
--- llvm/test/CodeGen/X86/stack-folding-fp-sse42.ll
+++ llvm/test/CodeGen/X86/stack-folding-fp-sse42.ll
@@ -583,7 +583,6 @@
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    nop
 ; CHECK-NEXT:    #NO_APP
-; CHECK-NEXT:    xorps %xmm0, %xmm0
 ; CHECK-NEXT:    cvtsd2ss {{[-0-9]+}}(%r{{[sb]}}p), %xmm0 # 8-byte Folded Reload
 ; CHECK-NEXT:    retq
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()
@@ -975,7 +974,6 @@
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    nop
 ; CHECK-NEXT:    #NO_APP
-; CHECK-NEXT:    xorps %xmm0, %xmm0
 ; CHECK-NEXT:    cvtss2sd {{[-0-9]+}}(%r{{[sb]}}p), %xmm0 # 4-byte Folded Reload
 ; CHECK-NEXT:    retq
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()
@@ -2012,7 +2010,6 @@
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    nop
 ; CHECK-NEXT:    #NO_APP
-; CHECK-NEXT:    xorps %xmm0, %xmm0
 ; CHECK-NEXT:    roundss $9, {{[-0-9]+}}(%r{{[sb]}}p), %xmm0 # 4-byte Folded Reload
 ; CHECK-NEXT:    retq
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()
@@ -2181,7 +2178,6 @@
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    nop
 ; CHECK-NEXT:    #NO_APP
-; CHECK-NEXT:    xorps %xmm0, %xmm0
 ; CHECK-NEXT:    sqrtss {{[-0-9]+}}(%r{{[sb]}}p), %xmm0 # 4-byte Folded Reload
 ; CHECK-NEXT:    retq
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()
Index: llvm/test/CodeGen/X86/sqrt-partial.ll
===================================================================
--- llvm/test/CodeGen/X86/sqrt-partial.ll
+++ llvm/test/CodeGen/X86/sqrt-partial.ll
@@ -67,7 +67,6 @@
 ; SSE-NEXT:    mulsd %xmm0, %xmm0
 ; SSE-NEXT:    mulsd %xmm1, %xmm1
 ; SSE-NEXT:    addsd %xmm0, %xmm1
-; SSE-NEXT:    xorps %xmm0, %xmm0
 ; SSE-NEXT:    sqrtsd %xmm1, %xmm0
 ; SSE-NEXT:    retq
 ;
Index: llvm/test/CodeGen/ARM/a15-partial-update.ll
===================================================================
--- llvm/test/CodeGen/ARM/a15-partial-update.ll
+++ llvm/test/CodeGen/ARM/a15-partial-update.ll
@@ -56,6 +56,8 @@
   ret void
 }
 
+; If minimizing size, that overrides perf, so no extra vmov.f64 here.
+
 define void @t2_minsize(<4 x i8> *%in, <4 x i8> *%out, i32 %n) minsize {
 ; CHECK-LABEL: t2_minsize:
 ; CHECK:       @ %bb.0: @ %entry
@@ -63,7 +65,6 @@
 ; CHECK-NEXT:    add r1, r1, #4
 ; CHECK-NEXT:  .LBB2_1: @ %loop
 ; CHECK-NEXT:    @ =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    vmov.f64 d16, #5.000000e-01
 ; CHECK-NEXT:    vld1.32 {d16[0]}, [r0:32]
 ; CHECK-NEXT:    vmovl.u8 q8, d16
 ; CHECK-NEXT:    vuzp.8 d16, d18
Index: llvm/lib/CodeGen/BreakFalseDeps.cpp
===================================================================
--- llvm/lib/CodeGen/BreakFalseDeps.cpp
+++ llvm/lib/CodeGen/BreakFalseDeps.cpp
@@ -251,6 +251,12 @@
 bool BreakFalseDeps::runOnMachineFunction(MachineFunction &mf) {
   if (skipFunction(mf.getFunction()))
     return false;
+
+  // This pass adds instructions to remove dependencies. That opposes the goal
+  // of minimizing size.
+  if (mf.getFunction().hasMinSize())
+    return false;
+
   MF = &mf;
   TII = MF->getSubtarget().getInstrInfo();
   TRI = MF->getSubtarget().getRegisterInfo();


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