[Beignet] [PATCH] GBE: fix regression caused by simple block optimization.
Zhigang Gong
zhigang.gong at intel.com
Wed Oct 22 23:25:56 PDT 2014
Almost all 64bit related instructions and unaligned load
instruction should be complex instruction. We need to exclude
them from simple block.
Signed-off-by: Zhigang Gong <zhigang.gong at intel.com>
---
backend/src/backend/gen_insn_selection.cpp | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/backend/src/backend/gen_insn_selection.cpp b/backend/src/backend/gen_insn_selection.cpp
index 1a37ef1..605fdd5 100644
--- a/backend/src/backend/gen_insn_selection.cpp
+++ b/backend/src/backend/gen_insn_selection.cpp
@@ -407,6 +407,8 @@ namespace gbe
void matchBasicBlock(const ir::BasicBlock &bb, uint32_t insnNum);
/*! a simple block can use predication instead of if/endif*/
bool isSimpleBlock(const ir::BasicBlock &bb, uint32_t insnNum);
+ /*! an instruction has a QWORD family src or dst operand. */
+ bool hasQWord(const ir::Instruction &insn);
/*! A root instruction needs to be generated */
bool isRoot(const ir::Instruction &insn) const;
@@ -1494,6 +1496,20 @@ namespace gbe
return false;
}
+ bool Selection::Opaque::hasQWord(const ir::Instruction &insn) {
+ for (uint32_t i = 0; i < insn.getSrcNum(); i++) {
+ const ir::Register reg = insn.getSrc(i);
+ if (getRegisterFamily(reg) == ir::FAMILY_QWORD)
+ return true;
+ }
+ for (uint32_t i = 0; i < insn.getDstNum(); i++) {
+ const ir::Register reg = insn.getDst(i);
+ if (getRegisterFamily(reg) == ir::FAMILY_QWORD)
+ return true;
+ }
+ return false;
+ }
+
bool Selection::Opaque::isSimpleBlock(const ir::BasicBlock &bb, uint32_t insnNum) {
// FIXME should include structured innermost if/else/endif
@@ -1511,6 +1527,18 @@ namespace gbe
insn.getOpcode() == ir::OP_SIMD_ALL ||
insn.getOpcode() == ir::OP_ELSE)
return false;
+
+ // Most of the QWord(long) related instruction introduce some CMP or
+ // more than 10 actual instructions at latter stage.
+ if (hasQWord(insn))
+ return false;
+
+ // Unaligned load may introduce CMP instruction.
+ if ( insn.isMemberOf<ir::LoadInstruction>()) {
+ const ir::LoadInstruction &ld = ir::cast<ir::LoadInstruction>(insn);
+ if (!ld.isAligned())
+ return false;
+ }
}
// there would generate a extra CMP instruction for predicated BRA with extern flag,
--
1.8.3.2
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