[PATCH] D78905: [RISCV] Tests for indirect float conversion

[Sam Elliott via Phabricator via llvm-commits]

lenary created this revision.
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lenary added a child revision: D78906: [RISCV] Add patterns for indirect float conversions.

I worked on some patterns to address the code generated by these
examples, which came out of some differential testing against GCC. The patterns
will be in a follow-up patch.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78905

Files:
  llvm/test/CodeGen/RISCV/double-convert-indirect.ll


Index: llvm/test/CodeGen/RISCV/double-convert-indirect.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/RISCV/double-convert-indirect.ll
@@ -0,0 +1,50 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -mattr=+f,+d -verify-machineinstrs < %s \
+; RUN:   | FileCheck -check-prefix=RV32IFD %s
+; RUN: llc -mtriple=riscv64 -mattr=+f,+d -verify-machineinstrs < %s \
+; RUN:   | FileCheck -check-prefix=RV64IFD %s
+
+;; These testcases check that we merge sequences of `fcvt.d.wu; fcvt.s.d` into
+;; `fcvt.s.wu`.
+;;
+;; TODO: Unfortunately, though this only uses 32-bit FP instructions, we cannot
+;; do this optimisation without the D extension as we need 64-bit FP values to
+;; be legal to get the right operands to match.
+
+define float @fcvt_s_w_via_d(i32 %0) nounwind {
+; RV32IFD-LABEL: fcvt_s_w_via_d:
+; RV32IFD:       # %bb.0:
+; RV32IFD-NEXT:    fcvt.d.w ft0, a0
+; RV32IFD-NEXT:    fcvt.s.d ft0, ft0
+; RV32IFD-NEXT:    fmv.x.w a0, ft0
+; RV32IFD-NEXT:    ret
+;
+; RV64IFD-LABEL: fcvt_s_w_via_d:
+; RV64IFD:       # %bb.0:
+; RV64IFD-NEXT:    fcvt.d.w ft0, a0
+; RV64IFD-NEXT:    fcvt.s.d ft0, ft0
+; RV64IFD-NEXT:    fmv.x.w a0, ft0
+; RV64IFD-NEXT:    ret
+  %2 = sitofp i32 %0 to double
+  %3 = fptrunc double %2 to float
+  ret float %3
+}
+
+define float @fcvt_s_wu_via_d(i32 %0) nounwind {
+; RV32IFD-LABEL: fcvt_s_wu_via_d:
+; RV32IFD:       # %bb.0:
+; RV32IFD-NEXT:    fcvt.d.wu ft0, a0
+; RV32IFD-NEXT:    fcvt.s.d ft0, ft0
+; RV32IFD-NEXT:    fmv.x.w a0, ft0
+; RV32IFD-NEXT:    ret
+;
+; RV64IFD-LABEL: fcvt_s_wu_via_d:
+; RV64IFD:       # %bb.0:
+; RV64IFD-NEXT:    fcvt.d.wu ft0, a0
+; RV64IFD-NEXT:    fcvt.s.d ft0, ft0
+; RV64IFD-NEXT:    fmv.x.w a0, ft0
+; RV64IFD-NEXT:    ret
+  %2 = uitofp i32 %0 to double
+  %3 = fptrunc double %2 to float
+  ret float %3
+}


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