[llvm] r335462 - Revert change 335077 "[InlineSpiller] Fix a crash due to lack of forward progress from remat specifically for STATEPOINT"
Artur Pilipenko via llvm-commits
llvm-commits at lists.llvm.org
Mon Jun 25 05:58:13 PDT 2018
Author: apilipenko
Date: Mon Jun 25 05:58:13 2018
New Revision: 335462
URL: http://llvm.org/viewvc/llvm-project?rev=335462&view=rev
Log:
Revert change 335077 "[InlineSpiller] Fix a crash due to lack of forward progress from remat specifically for STATEPOINT"
This change caused widespread assertion failures in our downstream testing:
lib/CodeGen/LiveInterval.cpp:409: bool llvm::LiveRange::overlapsFrom(const llvm::LiveRange&, llvm::LiveRange::const_iterator) const: Assertion `!empty() && "empty range"' failed.
Modified:
llvm/trunk/lib/CodeGen/InlineSpiller.cpp
llvm/trunk/test/CodeGen/X86/statepoint-live-in.ll
Modified: llvm/trunk/lib/CodeGen/InlineSpiller.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/InlineSpiller.cpp?rev=335462&r1=335461&r2=335462&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/InlineSpiller.cpp (original)
+++ llvm/trunk/lib/CodeGen/InlineSpiller.cpp Mon Jun 25 05:58:13 2018
@@ -215,7 +215,6 @@ private:
void eliminateRedundantSpills(LiveInterval &LI, VNInfo *VNI);
void markValueUsed(LiveInterval*, VNInfo*);
- bool canGuaranteeAssignmentAfterRemat(unsigned VReg, MachineInstr &MI);
bool reMaterializeFor(LiveInterval &, MachineInstr &MI);
void reMaterializeAll();
@@ -515,26 +514,6 @@ void InlineSpiller::markValueUsed(LiveIn
} while (!WorkList.empty());
}
-bool InlineSpiller::canGuaranteeAssignmentAfterRemat(unsigned VReg,
- MachineInstr &MI) {
- // Here's a quick explanation of the problem we're trying to handle here:
- // * There are some pseudo instructions with more vreg uses than there are
- // physical registers on the machine.
- // * This is normally handled by spilling the vreg, and folding the reload
- // into the user instruction. (Thus decreasing the number of used vregs
- // until the remainder can be assigned to physregs.)
- // * However, since we may try to spill vregs in any order, we can end up
- // trying to spill each operand to the instruction, and then rematting it
- // instead. When that happens, the new live intervals (for the remats) are
- // expected to be trivially assignable (i.e. RS_Done). However, since we
- // may have more remats than physregs, we're guaranteed to fail to assign
- // one.
- // At the moment, we only handle this for STATEPOINTs since they're the only
- // psuedo op where we've seen this. If we start seeing other instructions
- // with the same problem, we need to revisit this.
- return (MI.getOpcode() != TargetOpcode::STATEPOINT);
-}
-
/// reMaterializeFor - Attempt to rematerialize before MI instead of reloading.
bool InlineSpiller::reMaterializeFor(LiveInterval &VirtReg, MachineInstr &MI) {
// Analyze instruction
@@ -590,11 +569,6 @@ bool InlineSpiller::reMaterializeFor(Liv
return true;
}
- // If we can't guarantee that we'll be able to actually assign the new vreg,
- // we can't remat.
- if (!canGuaranteeAssignmentAfterRemat(VirtReg.reg, MI))
- return false;
-
// Allocate a new register for the remat.
unsigned NewVReg = Edit->createFrom(Original);
Modified: llvm/trunk/test/CodeGen/X86/statepoint-live-in.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/statepoint-live-in.ll?rev=335462&r1=335461&r2=335462&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/statepoint-live-in.ll (original)
+++ llvm/trunk/test/CodeGen/X86/statepoint-live-in.ll Mon Jun 25 05:58:13 2018
@@ -128,77 +128,6 @@ entry:
ret void
}
-; A variant of test7 where values are not directly foldable from stack slots.
-define void @test7(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, i32 %h, i32 %i, i32 %j, i32 %k, i32 %l, i32 %m, i32 %n, i32 %o, i32 %p, i32 %q, i32 %r, i32 %s, i32 %t, i32 %u, i32 %v, i32 %w, i32 %x, i32 %y, i32 %z) gc "statepoint-example" {
-; The code for this is terrible, check simply for correctness for the moment
-; CHECK-LABEL: test7:
-; CHECK: callq _bar
-entry:
- %a64 = zext i32 %a to i64
- %b64 = zext i32 %b to i64
- %c64 = zext i32 %c to i64
- %d64 = zext i32 %d to i64
- %e64 = zext i32 %e to i64
- %f64 = zext i32 %f to i64
- %g64 = zext i32 %g to i64
- %h64 = zext i32 %h to i64
- %i64 = zext i32 %i to i64
- %j64 = zext i32 %j to i64
- %k64 = zext i32 %k to i64
- %l64 = zext i32 %l to i64
- %m64 = zext i32 %m to i64
- %n64 = zext i32 %n to i64
- %o64 = zext i32 %o to i64
- %p64 = zext i32 %p to i64
- %q64 = zext i32 %q to i64
- %r64 = zext i32 %r to i64
- %s64 = zext i32 %s to i64
- %t64 = zext i32 %t to i64
- %u64 = zext i32 %u to i64
- %v64 = zext i32 %v to i64
- %w64 = zext i32 %w to i64
- %x64 = zext i32 %x to i64
- %y64 = zext i32 %y to i64
- %z64 = zext i32 %z to i64
- %statepoint_token1 = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 2882400000, i32 0, void ()* @bar, i32 0, i32 2, i32 0, i32 26, i64 %a64, i64 %b64, i64 %c64, i64 %d64, i64 %e64, i64 %f64, i64 %g64, i64 %h64, i64 %i64, i64 %j64, i64 %k64, i64 %l64, i64 %m64, i64 %n64, i64 %o64, i64 %p64, i64 %q64, i64 %r64, i64 %s64, i64 %t64, i64 %u64, i64 %v64, i64 %w64, i64 %x64, i64 %y64, i64 %z64)
- ret void
-}
-
-; a variant of test7 with mixed types chosen to exercise register aliases
-define void @test8(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, i32 %h, i32 %i, i32 %j, i32 %k, i32 %l, i32 %m, i32 %n, i32 %o, i32 %p, i32 %q, i32 %r, i32 %s, i32 %t, i32 %u, i32 %v, i32 %w, i32 %x, i32 %y, i32 %z) gc "statepoint-example" {
-; The code for this is terrible, check simply for correctness for the moment
-; CHECK-LABEL: test8:
-; CHECK: callq _bar
-entry:
- %a8 = trunc i32 %a to i8
- %b8 = trunc i32 %b to i8
- %c8 = trunc i32 %c to i8
- %d8 = trunc i32 %d to i8
- %e16 = trunc i32 %e to i16
- %f16 = trunc i32 %f to i16
- %g16 = trunc i32 %g to i16
- %h16 = trunc i32 %h to i16
- %i64 = zext i32 %i to i64
- %j64 = zext i32 %j to i64
- %k64 = zext i32 %k to i64
- %l64 = zext i32 %l to i64
- %m64 = zext i32 %m to i64
- %n64 = zext i32 %n to i64
- %o64 = zext i32 %o to i64
- %p64 = zext i32 %p to i64
- %q64 = zext i32 %q to i64
- %r64 = zext i32 %r to i64
- %s64 = zext i32 %s to i64
- %t64 = zext i32 %t to i64
- %u64 = zext i32 %u to i64
- %v64 = zext i32 %v to i64
- %w64 = zext i32 %w to i64
- %x64 = zext i32 %x to i64
- %y64 = zext i32 %y to i64
- %z64 = zext i32 %z to i64
- %statepoint_token1 = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 2882400000, i32 0, void ()* @bar, i32 0, i32 2, i32 0, i32 26, i8 %a8, i8 %b8, i8 %c8, i8 %d8, i16 %e16, i16 %f16, i16 %g16, i16 %h16, i64 %i64, i64 %j64, i64 %k64, i64 %l64, i64 %m64, i64 %n64, i64 %o64, i64 %p64, i64 %q64, i64 %r64, i64 %s64, i64 %t64, i64 %u64, i64 %v64, i64 %w64, i64 %x64, i64 %y64, i64 %z64)
- ret void
-}
; CHECK: Ltmp0-_test1
; CHECK: .byte 1
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