[llvm] [RISCV] Handled the uimm9 offset while FrameIndex folding. (PR #149303)

[Craig Topper via llvm-commits]

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@@ -49,3 +49,55 @@ define void @prefetch_inst_read(ptr noundef %ptr) nounwind  {
   tail call void @llvm.prefetch.p0(ptr nonnull %arrayidx, i32 0, i32 0, i32 0)
   ret void
 }
+
+define void @prefetch_frameindex_test_neg() nounwind {
+; RV32XMIPSPREFETCH-LABEL: prefetch_frameindex_test_neg:
+; RV32XMIPSPREFETCH:       # %bb.0:
+; RV32XMIPSPREFETCH-NEXT:    lui a0, 1
+; RV32XMIPSPREFETCH-NEXT:    addi a0, a0, 16
+; RV32XMIPSPREFETCH-NEXT:    sub sp, sp, a0
+; RV32XMIPSPREFETCH-NEXT:    addi a0, sp, 524
+; RV32XMIPSPREFETCH-NEXT:    mips.pref 8, 0(a0)
+; RV32XMIPSPREFETCH-NEXT:    lui a0, 1
+; RV32XMIPSPREFETCH-NEXT:    addi a0, a0, 16
+; RV32XMIPSPREFETCH-NEXT:    add sp, sp, a0
+; RV32XMIPSPREFETCH-NEXT:    ret
+;
+; RV64XMIPSPREFETCH-LABEL: prefetch_frameindex_test_neg:
+; RV64XMIPSPREFETCH:       # %bb.0:
+; RV64XMIPSPREFETCH-NEXT:    lui a0, 1
+; RV64XMIPSPREFETCH-NEXT:    addi a0, a0, 16
+; RV64XMIPSPREFETCH-NEXT:    sub sp, sp, a0
+; RV64XMIPSPREFETCH-NEXT:    addi a0, sp, 524
+; RV64XMIPSPREFETCH-NEXT:    mips.pref 8, 0(a0)
+; RV64XMIPSPREFETCH-NEXT:    lui a0, 1
+; RV64XMIPSPREFETCH-NEXT:    addi a0, a0, 16
+; RV64XMIPSPREFETCH-NEXT:    add sp, sp, a0
+; RV64XMIPSPREFETCH-NEXT:    ret
+  %data = alloca [1024 x i32], align 4
+  %base = bitcast ptr %data to ptr
+  %ptr = getelementptr [127 x i32], ptr %base, i32 0, i32 127
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topperc wrote:

Why did we need to from 1024xi32 to 127 x i32?

https://github.com/llvm/llvm-project/pull/149303