[llvm] [RISCV][GISel] Port AddiPair optimization (PR #120463)

[Michael Maitland via llvm-commits]

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@@ -0,0 +1,247 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -global-isel < %s \
+; RUN: | FileCheck %s -check-prefix=RV32I
+; RUN: llc -mtriple=riscv64 -global-isel < %s \
+; RUN: | FileCheck %s -check-prefix=RV64I
+
+; These test how the immediate in an addition is materialized.
+
+define i32 @add_positive_low_bound_reject(i32 %a) nounwind {
+; RV32I-LABEL: add_positive_low_bound_reject:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_positive_low_bound_reject:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 2047
+  ret i32 %1
+}
+
+define i32 @add_positive_low_bound_accept(i32 %a) nounwind {
+; RV32I-LABEL: add_positive_low_bound_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    addi a0, a0, 1
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_positive_low_bound_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    addi a0, a0, 1
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 2048
+  ret i32 %1
+}
+
+define i32 @add_positive_high_bound_accept(i32 %a) nounwind {
+; RV32I-LABEL: add_positive_high_bound_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_positive_high_bound_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 4094
+  ret i32 %1
+}
+
+define i32 @add_positive_high_bound_reject(i32 %a) nounwind {
+; RV32I-LABEL: add_positive_high_bound_reject:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    lui a1, 1
+; RV32I-NEXT:    addi a1, a1, -1
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_positive_high_bound_reject:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    lui a1, 1
+; RV64I-NEXT:    addiw a1, a1, -1
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 4095
+  ret i32 %1
+}
+
+define i32 @add_negative_high_bound_reject(i32 %a) nounwind {
+; RV32I-LABEL: add_negative_high_bound_reject:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, -2048
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_negative_high_bound_reject:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, -2048
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, -2048
+  ret i32 %1
+}
+
+define i32 @add_negative_high_bound_accept(i32 %a) nounwind {
+; RV32I-LABEL: add_negative_high_bound_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, -2048
+; RV32I-NEXT:    addi a0, a0, -1
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_negative_high_bound_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, -2048
+; RV64I-NEXT:    addi a0, a0, -1
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, -2049
+  ret i32 %1
+}
+
+define i32 @add_negative_low_bound_accept(i32 %a) nounwind {
+; RV32I-LABEL: add_negative_low_bound_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, -2048
+; RV32I-NEXT:    addi a0, a0, -2048
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_negative_low_bound_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, -2048
+; RV64I-NEXT:    addi a0, a0, -2048
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, -4096
+  ret i32 %1
+}
+
+define i32 @add_negative_low_bound_reject(i32 %a) nounwind {
+; RV32I-LABEL: add_negative_low_bound_reject:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    lui a1, 1048575
+; RV32I-NEXT:    addi a1, a1, -1
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add_negative_low_bound_reject:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    lui a1, 1048575
+; RV64I-NEXT:    addiw a1, a1, -1
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, -4097
+  ret i32 %1
+}
+
+define i32 @add32_accept(i32 %a) nounwind {
+; RV32I-LABEL: add32_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    addi a0, a0, 952
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add32_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    addi a0, a0, 952
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 2999
+  ret i32 %1
+}
+
+define signext i32 @add32_sext_accept(i32 signext %a) nounwind {
+; RV32I-LABEL: add32_sext_accept:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    addi a0, a0, 952
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add32_sext_accept:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    addiw a0, a0, 952
+; RV64I-NEXT:    ret
+  %1 = add i32 %a, 2999
+  ret i32 %1
+}
+
+ at gv0 = global i32 0, align 4
+define signext i32 @add32_sext_reject_on_rv64(i32 signext %a) nounwind {
+; RV32I-LABEL: add32_sext_reject_on_rv64:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    lui a1, %hi(gv0)
+; RV32I-NEXT:    addi a0, a0, 2047
+; RV32I-NEXT:    addi a0, a0, 953
+; RV32I-NEXT:    sw a0, %lo(gv0)(a1)
+; RV32I-NEXT:    ret
+;
+; RV64I-LABEL: add32_sext_reject_on_rv64:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    lui a1, %hi(gv0)
+; RV64I-NEXT:    addi a0, a0, 2047
+; RV64I-NEXT:    addiw a0, a0, 953
+; RV64I-NEXT:    sw a0, %lo(gv0)(a1)
+; RV64I-NEXT:    ret
+  %b = add nsw i32 %a, 3000
+  store i32 %b, ptr @gv0, align 4
+  ret i32 %b
+}
+
+define i64 @add64_accept(i64 %a) nounwind {
+; RV32I-LABEL: add64_accept:
----------------
michaelmaitland wrote:

Good point

https://github.com/llvm/llvm-project/pull/120463