[RISCV] Add CostModel GEP tests

[luismarques]

Summary

These tests revolve around checking that the implied offsets fit the simm12 immediates. When they do, the offsets can be folded into the loads/stores, and therefore they should have zero cost.
The patch adds vector tests, despite the RISC-V backend currently not targetting any vector units. That was a borderline decision. Since we can compile IR vector instructions to scalar native ones, I felt including the vector tests made sense. This way we also have the infrastructure already in place for when we decide to add support for vector extensions.

[asb]

I think it would make sense to combine the RV32I and RV64I check lines into a shared RVI check-prefix, as I don't think we're expecting different cost model answers for RV32 vs RV64?

[luismarques]

In D61185#1513477, @asb wrote:

I think it would make sense to combine the RV32I and RV64I check lines into a shared RVI check-prefix, as I don't think we're expecting different cost model answers for RV32 vs RV64?

That sounds sensible. I did a quick review, to see if there might have been a plausible reason for the split, and I couldn't find any. Will change.

[luismarques]

Removed the RV64I check prefixes and renamed the RV32I prefix to RVI.

[asb]

test/Analysis/CostModel/RISCV/gep.ll

2 ↗

(On Diff #201189)

You want a -mtriple=riscv64 RUN line here, but with the same RVI check-prefix

[luismarques]

Now with two check lines, checking against a common prefix.

[asb]

LGTM with minor nit

test/Analysis/CostModel/RISCV/gep.ll

18 ↗

(On Diff #201244)

Nit: I think these empty comment lines are unwanted and an artifact of when there were two different check prefixes

[luismarques]

test/Analysis/CostModel/RISCV/gep.ll

18 ↗

(On Diff #201244)

As discussed with @asb in person, and for future reference, update_analyze_test_checks.py does add the empty comment lines, while update_llc_test_checks.py does not.

llvm/trunk/test/Analysis/CostModel/RISCV/gep.ll

+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt -mtriple=riscv32 -cost-model -analyze < %s \
+; RUN:   | FileCheck %s -check-prefix=RVI
+; RUN: opt -mtriple=riscv64 -cost-model -analyze < %s \
+; RUN:   | FileCheck %s -check-prefix=RVI
+
+define void @testi8(i8* %a, i32 %i) {
+; RVI-LABEL: 'testi8'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds i8, i8* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds i8, i8* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds i8, i8* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds i8, i8* %a, i32 2047
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds i8, i8* %a, i32 2048
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds i8, i8* %a, i32 -2048
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds i8, i8* %a, i32 -2049
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds i8, i8* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds i8, i8* %a, i32 0
+  %a1 = getelementptr inbounds i8, i8* %a, i32 1
+  %a2 = getelementptr inbounds i8, i8* %a, i32 -1
+  %a3 = getelementptr inbounds i8, i8* %a, i32 2047
+  %a4 = getelementptr inbounds i8, i8* %a, i32 2048
+  %a5 = getelementptr inbounds i8, i8* %a, i32 -2048
+  %a6 = getelementptr inbounds i8, i8* %a, i32 -2049
+  %ai = getelementptr inbounds i8, i8* %a, i32 %i
+  ret void
+}
+
+define void @testi16(i16* %a, i32 %i) {
+; RVI-LABEL: 'testi16'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds i16, i16* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds i16, i16* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds i16, i16* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds i16, i16* %a, i32 1023
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds i16, i16* %a, i32 1024
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds i16, i16* %a, i32 -1024
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds i16, i16* %a, i32 -1025
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds i16, i16* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds i16, i16* %a, i32 0
+  %a1 = getelementptr inbounds i16, i16* %a, i32 1
+  %a2 = getelementptr inbounds i16, i16* %a, i32 -1
+  %a3 = getelementptr inbounds i16, i16* %a, i32 1023
+  %a4 = getelementptr inbounds i16, i16* %a, i32 1024
+  %a5 = getelementptr inbounds i16, i16* %a, i32 -1024
+  %a6 = getelementptr inbounds i16, i16* %a, i32 -1025
+  %ai = getelementptr inbounds i16, i16* %a, i32 %i
+  ret void
+}
+
+define void @testi32(i32* %a, i32 %i) {
+; RVI-LABEL: 'testi32'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds i32, i32* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds i32, i32* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds i32, i32* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds i32, i32* %a, i32 511
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds i32, i32* %a, i32 512
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds i32, i32* %a, i32 -512
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds i32, i32* %a, i32 -513
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds i32, i32* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds i32, i32* %a, i32 0
+  %a1 = getelementptr inbounds i32, i32* %a, i32 1
+  %a2 = getelementptr inbounds i32, i32* %a, i32 -1
+  %a3 = getelementptr inbounds i32, i32* %a, i32 511
+  %a4 = getelementptr inbounds i32, i32* %a, i32 512
+  %a5 = getelementptr inbounds i32, i32* %a, i32 -512
+  %a6 = getelementptr inbounds i32, i32* %a, i32 -513
+  %ai = getelementptr inbounds i32, i32* %a, i32 %i
+  ret void
+}
+
+define void @testi64(i64* %a, i32 %i) {
+; RVI-LABEL: 'testi64'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds i64, i64* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds i64, i64* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds i64, i64* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds i64, i64* %a, i32 255
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds i64, i64* %a, i32 256
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds i64, i64* %a, i32 -256
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds i64, i64* %a, i32 -257
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds i64, i64* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds i64, i64* %a, i32 0
+  %a1 = getelementptr inbounds i64, i64* %a, i32 1
+  %a2 = getelementptr inbounds i64, i64* %a, i32 -1
+  %a3 = getelementptr inbounds i64, i64* %a, i32 255
+  %a4 = getelementptr inbounds i64, i64* %a, i32 256
+  %a5 = getelementptr inbounds i64, i64* %a, i32 -256
+  %a6 = getelementptr inbounds i64, i64* %a, i32 -257
+  %ai = getelementptr inbounds i64, i64* %a, i32 %i
+  ret void
+}
+
+define void @testfloat(float* %a, i32 %i) {
+; RVI-LABEL: 'testfloat'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds float, float* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds float, float* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds float, float* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds float, float* %a, i32 511
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds float, float* %a, i32 512
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds float, float* %a, i32 -512
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds float, float* %a, i32 -513
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds float, float* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds float, float* %a, i32 0
+  %a1 = getelementptr inbounds float, float* %a, i32 1
+  %a2 = getelementptr inbounds float, float* %a, i32 -1
+  %a3 = getelementptr inbounds float, float* %a, i32 511
+  %a4 = getelementptr inbounds float, float* %a, i32 512
+  %a5 = getelementptr inbounds float, float* %a, i32 -512
+  %a6 = getelementptr inbounds float, float* %a, i32 -513
+  %ai = getelementptr inbounds float, float* %a, i32 %i
+  ret void
+}
+
+define void @testdouble(double* %a, i32 %i) {
+; RVI-LABEL: 'testdouble'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds double, double* %a, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds double, double* %a, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds double, double* %a, i32 -1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds double, double* %a, i32 255
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a4 = getelementptr inbounds double, double* %a, i32 256
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds double, double* %a, i32 -256
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a6 = getelementptr inbounds double, double* %a, i32 -257
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds double, double* %a, i32 %i
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds double, double* %a, i32 0
+  %a1 = getelementptr inbounds double, double* %a, i32 1
+  %a2 = getelementptr inbounds double, double* %a, i32 -1
+  %a3 = getelementptr inbounds double, double* %a, i32 255
+  %a4 = getelementptr inbounds double, double* %a, i32 256
+  %a5 = getelementptr inbounds double, double* %a, i32 -256
+  %a6 = getelementptr inbounds double, double* %a, i32 -257
+  %ai = getelementptr inbounds double, double* %a, i32 %i
+  ret void
+}
+
+define void @testvecs(i32 %i) {
+; RVI-LABEL: 'testvecs'
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a2 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a3 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a4 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a5 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 0
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b0 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b1 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b2 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b3 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b4 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %b5 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 1
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %c1 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %c2 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %c3 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %c4 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %c5 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %c6 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 128
+; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %a0 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 0
+  %a1 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 0
+  %a2 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 0
+  %a3 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 0
+  %a4 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 0
+  %a5 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 0
+
+  %b0 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 1
+  %b1 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 1
+  %b2 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 1
+  %b3 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 1
+  %b4 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 1
+  %b5 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 1
+
+  %c1 = getelementptr inbounds <4 x i8>, <4 x i8>* undef, i32 128
+  %c2 = getelementptr inbounds <4 x i16>, <4 x i16>* undef, i32 128
+  %c3 = getelementptr inbounds <4 x i32>, <4 x i32>* undef, i32 128
+  %c4 = getelementptr inbounds <4 x i64>, <4 x i64>* undef, i32 128
+  %c5 = getelementptr inbounds <4 x float>, <4 x float>* undef, i32 128
+  %c6 = getelementptr inbounds <4 x double>, <4 x double>* undef, i32 128
+
+  ret void
+}