diff options
| -rw-r--r-- | lib/CodeGen/RegAllocGreedy.cpp | 20 | ||||
| -rw-r--r-- | test/CodeGen/X86/ragreedy-last-chance-recoloring.ll | 5 |
2 files changed, 19 insertions, 6 deletions
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp index e65398f592..7a120e8802 100644 --- a/lib/CodeGen/RegAllocGreedy.cpp +++ b/lib/CodeGen/RegAllocGreedy.cpp @@ -73,6 +73,11 @@ static cl::opt<unsigned> LastChanceRecoloringMaxInterference( " interference at a time"), cl::init(8)); +static cl::opt<bool> +ExhaustiveSearch("fexhaustive-register-search", cl::NotHidden, + cl::desc("Exhaustive Search for registers bypassing the depth " + "and interference cutoffs of last chance recoloring")); + // FIXME: Find a good default for this flag and remove the flag. static cl::opt<unsigned> CSRFirstTimeCost("regalloc-csr-first-time-cost", @@ -1932,7 +1937,7 @@ RAGreedy::mayRecolorAllInterferences(unsigned PhysReg, LiveInterval &VirtReg, // If there is LastChanceRecoloringMaxInterference or more interferences, // chances are one would not be recolorable. if (Q.collectInterferingVRegs(LastChanceRecoloringMaxInterference) >= - LastChanceRecoloringMaxInterference) { + LastChanceRecoloringMaxInterference && !ExhaustiveSearch) { DEBUG(dbgs() << "Early abort: too many interferences.\n"); CutOffInfo |= CO_Interf; return false; @@ -2005,7 +2010,7 @@ unsigned RAGreedy::tryLastChanceRecoloring(LiveInterval &VirtReg, // We may want to reconsider that if we end up with a too large search space // for target with hundreds of registers. // Indeed, in that case we may want to cut the search space earlier. - if (Depth >= LastChanceRecoloringMaxDepth) { + if (Depth >= LastChanceRecoloringMaxDepth && !ExhaustiveSearch) { DEBUG(dbgs() << "Abort because max depth has been reached.\n"); CutOffInfo |= CO_Depth; return ~0u; @@ -2139,14 +2144,17 @@ unsigned RAGreedy::selectOrSplit(LiveInterval &VirtReg, if (Reg == ~0U && (CutOffInfo != CO_None)) { uint8_t CutOffEncountered = CutOffInfo & (CO_Depth | CO_Interf); if (CutOffEncountered == CO_Depth) - Ctx.emitError( - "register allocation failed: maximum depth for recoloring reached"); + Ctx.emitError("register allocation failed: maximum depth for recoloring " + "reached. Use -fexhaustive-register-search to skip " + "cutoffs"); else if (CutOffEncountered == CO_Interf) Ctx.emitError("register allocation failed: maximum interference for " - "recoloring reached"); + "recoloring reached. Use -fexhaustive-register-search " + "to skip cutoffs"); else if (CutOffEncountered == (CO_Depth | CO_Interf)) Ctx.emitError("register allocation failed: maximum interference and " - "depth for recoloring reached"); + "depth for recoloring reached. Use " + "-fexhaustive-register-search to skip cutoffs"); } return Reg; } diff --git a/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll b/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll index 830a10d36f..e21e2dd5df 100644 --- a/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll +++ b/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll @@ -8,6 +8,10 @@ ; RUN: not llc -regalloc=greedy -relocation-model=pic -lcr-max-interf=1 < %s 2>&1 | FileCheck %s --check-prefix=CHECK-INTERF ; Test whether failure due to cutoff for interference is reported +; RUN: llc -regalloc=greedy -relocation-model=pic -lcr-max-interf=1 -lcr-max-depth=0 -fexhaustive-register-search < %s > %t 2>&1 +; RUN: FileCheck --input-file=%t %s --check-prefix=CHECK-EXHAUSTIVE +; Test whether fexhaustive-register-search can bypass the depth and interference cutoffs of last chance recoloring + target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32-S128" target triple = "i386-apple-macosx" @@ -20,6 +24,7 @@ target triple = "i386-apple-macosx" ; CHECK-NOT: ran out of registers during register allocation ; CHECK-INTERF: error: register allocation failed: maximum interference for recoloring reached ; CHECK-DEPTH: error: register allocation failed: maximum depth for recoloring reached +; CHECK-EXHAUSTIVE-NOT: error: register allocation failed: maximum {{depth|interference}} for recoloring reached define void @fp_dh_f870bf31fd8ffe068450366e3f05389a(i8* %arg) #0 { bb: indirectbr i8* undef, [label %bb85, label %bb206] |