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[WebAssembly] Optimize away mask of 63 for sra and srl( zext (and i32 63))) #170128

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Merged
badumbatish merged 3 commits into from
Dec 2, 2025
Merged

[WebAssembly] Optimize away mask of 63 for sra and srl( zext (and i32 63))) #170128

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bb9b1a9
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badumbatish Dec 1, 2025
219c674
Optimize away mask of 63 for sra and srl ( zext (and i32 63)))
badumbatish Dec 1, 2025
89b3cf1
Fix added extra newline
badumbatish Dec 2, 2025
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4 changes: 4 additions & 0 deletions llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td
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Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,10 @@ def : Pat<(rotr I64:$lhs, (and I64:$rhs, 63)), (ROTR_I64 I64:$lhs, I64:$rhs)>;

def : Pat<(shl I64:$lhs, (zext (and I32:$rhs, 63))),
(SHL_I64 I64:$lhs, (I64_EXTEND_U_I32 I32:$rhs))>;
def : Pat<(sra I64:$lhs, (zext (and I32:$rhs, 63))),
(SHR_S_I64 I64:$lhs, (I64_EXTEND_U_I32 I32:$rhs))>;
def : Pat<(srl I64:$lhs, (zext (and I32:$rhs, 63))),
(SHR_U_I64 I64:$lhs, (I64_EXTEND_U_I32 I32:$rhs))>;

defm SELECT_I32 : I<(outs I32:$dst), (ins I32:$lhs, I32:$rhs, I32:$cond),
(outs), (ins),
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30 changes: 30 additions & 0 deletions llvm/test/CodeGen/WebAssembly/masked-shifts.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,21 @@ define i32 @sra_i32(i32 %v, i32 %x) {
ret i32 %a
}

define i64 @sra_i64_zext(i64 %v, i32 %x) {
; CHECK-LABEL: sra_i64_zext:
; CHECK: .functype sra_i64_zext (i64, i32) -> (i64)
; CHECK-NEXT: # %bb.0:
; CHECK-NEXT: local.get 0
; CHECK-NEXT: local.get 1
; CHECK-NEXT: i64.extend_i32_u
; CHECK-NEXT: i64.shr_s
; CHECK-NEXT: # fallthrough-return
%m = and i32 %x, 63
%z = zext i32 %m to i64
%a = ashr i64 %v, %z
ret i64 %a
}

define i32 @srl_i32(i32 %v, i32 %x) {
; CHECK-LABEL: srl_i32:
; CHECK: .functype srl_i32 (i32, i32) -> (i32)
Expand All @@ -59,6 +74,21 @@ define i32 @srl_i32(i32 %v, i32 %x) {
ret i32 %a
}

define i64 @srl_i64_zext(i64 %v, i32 %x) {
; CHECK-LABEL: srl_i64_zext:
; CHECK: .functype srl_i64_zext (i64, i32) -> (i64)
; CHECK-NEXT: # %bb.0:
; CHECK-NEXT: local.get 0
; CHECK-NEXT: local.get 1
; CHECK-NEXT: i64.extend_i32_u
; CHECK-NEXT: i64.shr_u
; CHECK-NEXT: # fallthrough-return
%m = and i32 %x, 63
%z = zext i32 %m to i64
%a = lshr i64 %v, %z
ret i64 %a
}

define i64 @shl_i64(i64 %v, i64 %x) {
; CHECK-LABEL: shl_i64:
; CHECK: .functype shl_i64 (i64, i64) -> (i64)
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