[llvm] [RISCV][VLOPT] Add support for integer multiply-add instructions (PR #112216)

[Luke Lau via llvm-commits]

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@@ -1248,6 +1248,203 @@ define <vscale x 4 x i64> @vwmulu_vx(<vscale x 4 x i32> %a, i32 %b, iXLen %vl) {
   ret <vscale x 4 x i64> %2
 }
 
+define <vscale x 4 x i32> @vmacc_vv(<vscale x 4 x i32> %a, <vscale x 4 x i32> %b, iXLen %vl) {
+; NOVLOPT-LABEL: vmacc_vv:
+; NOVLOPT:       # %bb.0:
+; NOVLOPT-NEXT:    vsetvli a1, zero, e32, m2, tu, ma
+; NOVLOPT-NEXT:    vmacc.vv v8, v8, v10
+; NOVLOPT-NEXT:    vsetvli zero, a0, e32, m2, ta, ma
+; NOVLOPT-NEXT:    vmul.vv v8, v8, v10
+; NOVLOPT-NEXT:    ret
+;
+; VLOPT-LABEL: vmacc_vv:
+; VLOPT:       # %bb.0:
+; VLOPT-NEXT:    vsetvli zero, a0, e32, m2, tu, ma
+; VLOPT-NEXT:    vmacc.vv v8, v8, v10
+; VLOPT-NEXT:    vsetvli zero, zero, e32, m2, ta, ma
+; VLOPT-NEXT:    vmul.vv v8, v8, v10
+; VLOPT-NEXT:    ret
+  %1 = call <vscale x 4 x i32> @llvm.riscv.vmacc.nxv4i32.nxv4i32(<vscale x 4 x i32> %a, <vscale x 4 x i32> %a, <vscale x 4 x i32> %b, iXLen -1, iXLen 0)
+  %2 = call <vscale x 4 x i32> @llvm.riscv.vmul.nxv4i32.nxv4i32(<vscale x 4 x i32> poison, <vscale x 4 x i32> %1, <vscale x 4 x i32> %b, iXLen %vl)
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lukel97 wrote:

Nit, use vadd for the user instead of vmul?

https://github.com/llvm/llvm-project/pull/112216