[PATCH] D62968: [ARM] Adjust isLegalT1AddressImmediate for non-legal types

Thu Jun 6 10:17:13 PDT 2019

dmgreen created this revision.
dmgreen added reviewers: SjoerdMeijer, efriedma, t.p.northover, samparker.
Herald added subscribers: hiraditya, kristof.beyls, javed.absar.
Herald added a project: LLVM.

Types such as float and i64's do not have legal loads in Thumb1, but will still be loaded with a LDR (or potentially multiple LDR's). As such we can treat the cost of addressing mode calculations as such and get some optimisation benefits.

Some of the tests are new, I'm just showing the differences for clarity.


https://reviews.llvm.org/D62968

Files:
  llvm/lib/Target/ARM/ARMISelLowering.cpp
  llvm/test/Analysis/CostModel/ARM/gep.ll


Index: llvm/test/Analysis/CostModel/ARM/gep.ll
===================================================================

--- llvm/test/Analysis/CostModel/ARM/gep.ll
+++ llvm/test/Analysis/CostModel/ARM/gep.ll
@@ -210,9 +210,9 @@
 define void @testi64(i64* %a, i32 %i) {
 ; CHECK-V6M-LABEL: 'testi64'
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds i64, i64* %a, i32 0
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1 = getelementptr inbounds i64, i64* %a, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds i64, i64* %a, i32 1
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am4 = getelementptr inbounds i64, i64* %a, i32 -1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a15 = getelementptr inbounds i64, i64* %a, i32 15
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a15 = getelementptr inbounds i64, i64* %a, i32 15
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a16 = getelementptr inbounds i64, i64* %a, i32 16
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a31 = getelementptr inbounds i64, i64* %a, i32 31
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a32 = getelementptr inbounds i64, i64* %a, i32 32
@@ -394,7 +394,7 @@
 define void @testfloat(float* %a, i32 %i) {
 ; CHECK-V6M-LABEL: 'testfloat'
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds float, float* %a, i32 0
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1 = getelementptr inbounds float, float* %a, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds float, float* %a, i32 1
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am1 = getelementptr inbounds float, float* %a, i32 -1
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a255 = getelementptr inbounds float, float* %a, i32 255
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a256 = getelementptr inbounds float, float* %a, i32 256
@@ -501,7 +501,7 @@
 define void @testdouble(double* %a, i32 %i) {
 ; CHECK-V6M-LABEL: 'testdouble'
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds double, double* %a, i32 0
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1 = getelementptr inbounds double, double* %a, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds double, double* %a, i32 1
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am1 = getelementptr inbounds double, double* %a, i32 -1
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a255 = getelementptr inbounds double, double* %a, i32 127
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a256 = getelementptr inbounds double, double* %a, i32 128
@@ -584,21 +584,21 @@
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a11 = getelementptr inbounds <4 x half>, <4 x half>* undef, i32 0
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a12 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 0
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a13 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 0
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b8 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b9 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b10 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b11 = getelementptr inbounds <4 x half>, <4 x half>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b12 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %b13 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 1
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 4
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o8 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 4
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o9 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 4
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b8 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b9 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b10 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b11 = getelementptr inbounds <4 x half>, <4 x half>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b12 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b13 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 1
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %o7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 4
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %o8 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 4
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %o9 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 4
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o10 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 4
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o11 = getelementptr inbounds <4 x half>, <4 x half>* undef, i32 4
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o12 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 4
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %o11 = getelementptr inbounds <4 x half>, <4 x half>* undef, i32 4
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %o12 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 4
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %o13 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 4
-; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %p7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 31
+; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %p7 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 31
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %p8 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 31
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %p9 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 31
 ; CHECK-V6M-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %p10 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 31
Index: llvm/lib/Target/ARM/ARMISelLowering.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -13265,7 +13265,6 @@
 
   unsigned Scale = 1;
   switch (VT.getSimpleVT().SimpleTy) {
-  default: return false;
   case MVT::i1:
   case MVT::i8:
     // Scale == 1;
@@ -13274,7 +13273,8 @@
     // Scale == 2;
     Scale = 2;
     break;
-  case MVT::i32:
+  default:
+    // On thumb1 we load most things (i32, i64, floats, etc) with a LDR
     // Scale == 4;
     Scale = 4;
     break;


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