llvm · asb · Jul 21, 2025 · Jun 18, 2025 · Jun 18, 2025 · Jun 18, 2025
diff --git a/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp b/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp
@@ -736,7 +736,8 @@ bool RISCVOptWInstrs::canonicalizeWSuffixes(MachineFunction &MF,
     for (MachineInstr &MI : MBB) {
       std::optional<unsigned> WOpc;
       std::optional<unsigned> NonWOpc;
-      switch (MI.getOpcode()) {
+      unsigned OrigOpc = MI.getOpcode();
+      switch (OrigOpc) {
       default:
         continue;
       case RISCV::ADDW:
@@ -786,7 +787,10 @@ bool RISCVOptWInstrs::canonicalizeWSuffixes(MachineFunction &MF,
         MadeChange = true;
         continue;
       }
-      if (ShouldPreferW && WOpc.has_value() && hasAllWUsers(MI, ST, MRI)) {
+      // LWU is always converted to LW when possible as 1) LW is compressible
+      // and 2) it helps minimise differences vs RV32.
+      if ((ShouldPreferW || OrigOpc == RISCV::LWU) && WOpc.has_value() &&
+          hasAllWUsers(MI, ST, MRI)) {
         LLVM_DEBUG(dbgs() << "Replacing " << MI);
         MI.setDesc(TII.get(WOpc.value()));
         MI.clearFlag(MachineInstr::MIFlag::NoSWrap);

diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/double-convert.ll b/llvm/test/CodeGen/RISCV/GlobalISel/double-convert.ll
@@ -246,17 +246,11 @@ define double @fcvt_d_wu(i32 %a) nounwind {
 }
 
 define double @fcvt_d_wu_load(ptr %p) nounwind {
-; RV32IFD-LABEL: fcvt_d_wu_load:
-; RV32IFD:       # %bb.0:
-; RV32IFD-NEXT:    lw a0, 0(a0)
-; RV32IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV32IFD-NEXT:    ret
-;
-; RV64IFD-LABEL: fcvt_d_wu_load:
-; RV64IFD:       # %bb.0:
-; RV64IFD-NEXT:    lwu a0, 0(a0)
-; RV64IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV64IFD-NEXT:    ret
+; CHECKIFD-LABEL: fcvt_d_wu_load:
+; CHECKIFD:       # %bb.0:
+; CHECKIFD-NEXT:    lw a0, 0(a0)
+; CHECKIFD-NEXT:    fcvt.d.wu fa0, a0
+; CHECKIFD-NEXT:    ret
 ;
 ; RV32I-LABEL: fcvt_d_wu_load:
 ; RV32I:       # %bb.0:

diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/float-convert.ll b/llvm/test/CodeGen/RISCV/GlobalISel/float-convert.ll
@@ -232,17 +232,11 @@ define float @fcvt_s_wu(i32 %a) nounwind {
 }
 
 define float @fcvt_s_wu_load(ptr %p) nounwind {
-; RV32IF-LABEL: fcvt_s_wu_load:
-; RV32IF:       # %bb.0:
-; RV32IF-NEXT:    lw a0, 0(a0)
-; RV32IF-NEXT:    fcvt.s.wu fa0, a0
-; RV32IF-NEXT:    ret
-;
-; RV64IF-LABEL: fcvt_s_wu_load:
-; RV64IF:       # %bb.0:
-; RV64IF-NEXT:    lwu a0, 0(a0)
-; RV64IF-NEXT:    fcvt.s.wu fa0, a0
-; RV64IF-NEXT:    ret
+; CHECKIF-LABEL: fcvt_s_wu_load:
+; CHECKIF:       # %bb.0:
+; CHECKIF-NEXT:    lw a0, 0(a0)
+; CHECKIF-NEXT:    fcvt.s.wu fa0, a0
+; CHECKIF-NEXT:    ret
 ;
 ; RV32I-LABEL: fcvt_s_wu_load:
 ; RV32I:       # %bb.0:

diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/rv64zbb.ll b/llvm/test/CodeGen/RISCV/GlobalISel/rv64zbb.ll
@@ -748,7 +748,7 @@ define signext i32 @ctpop_i32_load(ptr %p) nounwind {
 ;
 ; RV64ZBB-LABEL: ctpop_i32_load:
 ; RV64ZBB:       # %bb.0:
-; RV64ZBB-NEXT:    lwu a0, 0(a0)
+; RV64ZBB-NEXT:    lw a0, 0(a0)
 ; RV64ZBB-NEXT:    cpopw a0, a0
 ; RV64ZBB-NEXT:    ret
   %a = load i32, ptr %p

diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/rv64zbkb.ll b/llvm/test/CodeGen/RISCV/GlobalISel/rv64zbkb.ll
@@ -114,16 +114,16 @@ define i64 @pack_i64_2(i32 signext %a, i32 signext %b) nounwind {
 define i64 @pack_i64_3(ptr %0, ptr %1) {
 ; RV64I-LABEL: pack_i64_3:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    lwu a0, 0(a0)
+; RV64I-NEXT:    lw a0, 0(a0)
 ; RV64I-NEXT:    lwu a1, 0(a1)
 ; RV64I-NEXT:    slli a0, a0, 32
 ; RV64I-NEXT:    or a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64ZBKB-LABEL: pack_i64_3:
 ; RV64ZBKB:       # %bb.0:
-; RV64ZBKB-NEXT:    lwu a0, 0(a0)
-; RV64ZBKB-NEXT:    lwu a1, 0(a1)
+; RV64ZBKB-NEXT:    lw a0, 0(a0)
+; RV64ZBKB-NEXT:    lw a1, 0(a1)
 ; RV64ZBKB-NEXT:    pack a0, a1, a0
 ; RV64ZBKB-NEXT:    ret
   %3 = load i32, ptr %0, align 4

diff --git a/llvm/test/CodeGen/RISCV/atomic-signext.ll b/llvm/test/CodeGen/RISCV/atomic-signext.ll
@@ -4582,7 +4582,7 @@ define signext i32 @atomicrmw_and_i32_monotonic_crossbb(ptr %a, i1 %c) nounwind
 ; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    ret
 ; RV64I-NEXT:  .LBB56_2: # %else
-; RV64I-NEXT:    lwu a1, 0(a0)
+; RV64I-NEXT:    lw a1, 0(a0)
 ; RV64I-NEXT:    andi a2, a1, 1
 ; RV64I-NEXT:    sw a2, 0(a0)
 ; RV64I-NEXT:    sext.w a0, a1
@@ -4700,7 +4700,7 @@ define signext i32 @atomicrmw_nand_i32_monotonic_crossbb(ptr %a, i1 %c) nounwind
 ; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    ret
 ; RV64I-NEXT:  .LBB57_2: # %else
-; RV64I-NEXT:    lwu a1, 0(a0)
+; RV64I-NEXT:    lw a1, 0(a0)
 ; RV64I-NEXT:    andi a2, a1, 1
 ; RV64I-NEXT:    sw a2, 0(a0)
 ; RV64I-NEXT:    sext.w a0, a1

diff --git a/llvm/test/CodeGen/RISCV/bfloat-convert.ll b/llvm/test/CodeGen/RISCV/bfloat-convert.ll
@@ -1074,7 +1074,7 @@ define bfloat @fcvt_bf16_wu_load(ptr %p) nounwind {
 ;
 ; CHECK64ZFBFMIN-LABEL: fcvt_bf16_wu_load:
 ; CHECK64ZFBFMIN:       # %bb.0:
-; CHECK64ZFBFMIN-NEXT:    lwu a0, 0(a0)
+; CHECK64ZFBFMIN-NEXT:    lw a0, 0(a0)
 ; CHECK64ZFBFMIN-NEXT:    fcvt.s.wu fa5, a0
 ; CHECK64ZFBFMIN-NEXT:    fcvt.bf16.s fa0, fa5
 ; CHECK64ZFBFMIN-NEXT:    ret
@@ -1083,7 +1083,7 @@ define bfloat @fcvt_bf16_wu_load(ptr %p) nounwind {
 ; RV64ID:       # %bb.0:
 ; RV64ID-NEXT:    addi sp, sp, -16
 ; RV64ID-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64ID-NEXT:    lwu a0, 0(a0)
+; RV64ID-NEXT:    lw a0, 0(a0)
 ; RV64ID-NEXT:    fcvt.s.wu fa0, a0
 ; RV64ID-NEXT:    call __truncsfbf2
 ; RV64ID-NEXT:    fmv.x.w a0, fa0

diff --git a/llvm/test/CodeGen/RISCV/double-convert-strict.ll b/llvm/test/CodeGen/RISCV/double-convert-strict.ll
@@ -347,17 +347,11 @@ define double @fcvt_d_wu(i32 %a) nounwind strictfp {
 declare double @llvm.experimental.constrained.uitofp.f64.i32(i32, metadata, metadata)
 
 define double @fcvt_d_wu_load(ptr %p) nounwind strictfp {
-; RV32IFD-LABEL: fcvt_d_wu_load:
-; RV32IFD:       # %bb.0:
-; RV32IFD-NEXT:    lw a0, 0(a0)
-; RV32IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV32IFD-NEXT:    ret
-;
-; RV64IFD-LABEL: fcvt_d_wu_load:
-; RV64IFD:       # %bb.0:
-; RV64IFD-NEXT:    lwu a0, 0(a0)
-; RV64IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV64IFD-NEXT:    ret
+; CHECKIFD-LABEL: fcvt_d_wu_load:
+; CHECKIFD:       # %bb.0:
+; CHECKIFD-NEXT:    lw a0, 0(a0)
+; CHECKIFD-NEXT:    fcvt.d.wu fa0, a0
+; CHECKIFD-NEXT:    ret
 ;
 ; RV32IZFINXZDINX-LABEL: fcvt_d_wu_load:
 ; RV32IZFINXZDINX:       # %bb.0:
@@ -367,7 +361,7 @@ define double @fcvt_d_wu_load(ptr %p) nounwind strictfp {
 ;
 ; RV64IZFINXZDINX-LABEL: fcvt_d_wu_load:
 ; RV64IZFINXZDINX:       # %bb.0:
-; RV64IZFINXZDINX-NEXT:    lwu a0, 0(a0)
+; RV64IZFINXZDINX-NEXT:    lw a0, 0(a0)
 ; RV64IZFINXZDINX-NEXT:    fcvt.d.wu a0, a0
 ; RV64IZFINXZDINX-NEXT:    ret
 ;

diff --git a/llvm/test/CodeGen/RISCV/double-convert.ll b/llvm/test/CodeGen/RISCV/double-convert.ll
@@ -582,17 +582,11 @@ define double @fcvt_d_wu(i32 %a) nounwind {
 }
 
 define double @fcvt_d_wu_load(ptr %p) nounwind {
-; RV32IFD-LABEL: fcvt_d_wu_load:
-; RV32IFD:       # %bb.0:
-; RV32IFD-NEXT:    lw a0, 0(a0)
-; RV32IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV32IFD-NEXT:    ret
-;
-; RV64IFD-LABEL: fcvt_d_wu_load:
-; RV64IFD:       # %bb.0:
-; RV64IFD-NEXT:    lwu a0, 0(a0)
-; RV64IFD-NEXT:    fcvt.d.wu fa0, a0
-; RV64IFD-NEXT:    ret
+; CHECKIFD-LABEL: fcvt_d_wu_load:
+; CHECKIFD:       # %bb.0:
+; CHECKIFD-NEXT:    lw a0, 0(a0)
+; CHECKIFD-NEXT:    fcvt.d.wu fa0, a0
+; CHECKIFD-NEXT:    ret
 ;
 ; RV32IZFINXZDINX-LABEL: fcvt_d_wu_load:
 ; RV32IZFINXZDINX:       # %bb.0:
@@ -602,7 +596,7 @@ define double @fcvt_d_wu_load(ptr %p) nounwind {
 ;
 ; RV64IZFINXZDINX-LABEL: fcvt_d_wu_load:
 ; RV64IZFINXZDINX:       # %bb.0:
-; RV64IZFINXZDINX-NEXT:    lwu a0, 0(a0)
+; RV64IZFINXZDINX-NEXT:    lw a0, 0(a0)
 ; RV64IZFINXZDINX-NEXT:    fcvt.d.wu a0, a0
 ; RV64IZFINXZDINX-NEXT:    ret
 ;

diff --git a/llvm/test/CodeGen/RISCV/float-convert-strict.ll b/llvm/test/CodeGen/RISCV/float-convert-strict.ll
@@ -236,29 +236,17 @@ define float @fcvt_s_wu(i32 %a) nounwind strictfp {
 declare float @llvm.experimental.constrained.uitofp.f32.i32(i32 %a, metadata, metadata)
 
 define float @fcvt_s_wu_load(ptr %p) nounwind strictfp {
-; RV32IF-LABEL: fcvt_s_wu_load:
-; RV32IF:       # %bb.0:
-; RV32IF-NEXT:    lw a0, 0(a0)
-; RV32IF-NEXT:    fcvt.s.wu fa0, a0
-; RV32IF-NEXT:    ret
-;
-; RV64IF-LABEL: fcvt_s_wu_load:
-; RV64IF:       # %bb.0:
-; RV64IF-NEXT:    lwu a0, 0(a0)
-; RV64IF-NEXT:    fcvt.s.wu fa0, a0
-; RV64IF-NEXT:    ret
-;
-; RV32IZFINX-LABEL: fcvt_s_wu_load:
-; RV32IZFINX:       # %bb.0:
-; RV32IZFINX-NEXT:    lw a0, 0(a0)
-; RV32IZFINX-NEXT:    fcvt.s.wu a0, a0
-; RV32IZFINX-NEXT:    ret
+; CHECKIF-LABEL: fcvt_s_wu_load:
+; CHECKIF:       # %bb.0:
+; CHECKIF-NEXT:    lw a0, 0(a0)
+; CHECKIF-NEXT:    fcvt.s.wu fa0, a0
+; CHECKIF-NEXT:    ret
 ;
-; RV64IZFINX-LABEL: fcvt_s_wu_load:
-; RV64IZFINX:       # %bb.0:
-; RV64IZFINX-NEXT:    lwu a0, 0(a0)
-; RV64IZFINX-NEXT:    fcvt.s.wu a0, a0
-; RV64IZFINX-NEXT:    ret
+; CHECKIZFINX-LABEL: fcvt_s_wu_load:
+; CHECKIZFINX:       # %bb.0:
+; CHECKIZFINX-NEXT:    lw a0, 0(a0)
+; CHECKIZFINX-NEXT:    fcvt.s.wu a0, a0
+; CHECKIZFINX-NEXT:    ret
 ;
 ; RV32I-LABEL: fcvt_s_wu_load:
 ; RV32I:       # %bb.0:

diff --git a/llvm/test/CodeGen/RISCV/float-convert.ll b/llvm/test/CodeGen/RISCV/float-convert.ll
@@ -482,29 +482,17 @@ define float @fcvt_s_wu(i32 %a) nounwind {
 }
 
 define float @fcvt_s_wu_load(ptr %p) nounwind {
-; RV32IF-LABEL: fcvt_s_wu_load:
-; RV32IF:       # %bb.0:
-; RV32IF-NEXT:    lw a0, 0(a0)
-; RV32IF-NEXT:    fcvt.s.wu fa0, a0
-; RV32IF-NEXT:    ret
-;
-; RV64IF-LABEL: fcvt_s_wu_load:
-; RV64IF:       # %bb.0:
-; RV64IF-NEXT:    lwu a0, 0(a0)
-; RV64IF-NEXT:    fcvt.s.wu fa0, a0
-; RV64IF-NEXT:    ret
-;
-; RV32IZFINX-LABEL: fcvt_s_wu_load:
-; RV32IZFINX:       # %bb.0:
-; RV32IZFINX-NEXT:    lw a0, 0(a0)
-; RV32IZFINX-NEXT:    fcvt.s.wu a0, a0
-; RV32IZFINX-NEXT:    ret
+; CHECKIF-LABEL: fcvt_s_wu_load:
+; CHECKIF:       # %bb.0:
+; CHECKIF-NEXT:    lw a0, 0(a0)
+; CHECKIF-NEXT:    fcvt.s.wu fa0, a0
+; CHECKIF-NEXT:    ret
 ;
-; RV64IZFINX-LABEL: fcvt_s_wu_load:
-; RV64IZFINX:       # %bb.0:
-; RV64IZFINX-NEXT:    lwu a0, 0(a0)
-; RV64IZFINX-NEXT:    fcvt.s.wu a0, a0
-; RV64IZFINX-NEXT:    ret
+; CHECKIZFINX-LABEL: fcvt_s_wu_load:
+; CHECKIZFINX:       # %bb.0:
+; CHECKIZFINX-NEXT:    lw a0, 0(a0)
+; CHECKIZFINX-NEXT:    fcvt.s.wu a0, a0
+; CHECKIZFINX-NEXT:    ret
 ;
 ; RV32I-LABEL: fcvt_s_wu_load:
 ; RV32I:       # %bb.0:

diff --git a/llvm/test/CodeGen/RISCV/half-convert-strict.ll b/llvm/test/CodeGen/RISCV/half-convert-strict.ll
@@ -1461,29 +1461,17 @@ define half @fcvt_h_wu(i32 %a) nounwind strictfp {
 declare half @llvm.experimental.constrained.uitofp.f16.i32(i32, metadata, metadata)
 
 define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
-; RV32IZFH-LABEL: fcvt_h_wu_load:
-; RV32IZFH:       # %bb.0:
-; RV32IZFH-NEXT:    lw a0, 0(a0)
-; RV32IZFH-NEXT:    fcvt.h.wu fa0, a0
-; RV32IZFH-NEXT:    ret
-;
-; RV64IZFH-LABEL: fcvt_h_wu_load:
-; RV64IZFH:       # %bb.0:
-; RV64IZFH-NEXT:    lwu a0, 0(a0)
-; RV64IZFH-NEXT:    fcvt.h.wu fa0, a0
-; RV64IZFH-NEXT:    ret
-;
-; RV32IZHINX-LABEL: fcvt_h_wu_load:
-; RV32IZHINX:       # %bb.0:
-; RV32IZHINX-NEXT:    lw a0, 0(a0)
-; RV32IZHINX-NEXT:    fcvt.h.wu a0, a0
-; RV32IZHINX-NEXT:    ret
+; CHECKIZFH-LABEL: fcvt_h_wu_load:
+; CHECKIZFH:       # %bb.0:
+; CHECKIZFH-NEXT:    lw a0, 0(a0)
+; CHECKIZFH-NEXT:    fcvt.h.wu fa0, a0
+; CHECKIZFH-NEXT:    ret
 ;
-; RV64IZHINX-LABEL: fcvt_h_wu_load:
-; RV64IZHINX:       # %bb.0:
-; RV64IZHINX-NEXT:    lwu a0, 0(a0)
-; RV64IZHINX-NEXT:    fcvt.h.wu a0, a0
-; RV64IZHINX-NEXT:    ret
+; CHECKIZHINX-LABEL: fcvt_h_wu_load:
+; CHECKIZHINX:       # %bb.0:
+; CHECKIZHINX-NEXT:    lw a0, 0(a0)
+; CHECKIZHINX-NEXT:    fcvt.h.wu a0, a0
+; CHECKIZHINX-NEXT:    ret
 ;
 ; RV32IDZFH-LABEL: fcvt_h_wu_load:
 ; RV32IDZFH:       # %bb.0:
@@ -1493,7 +1481,7 @@ define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
 ;
 ; RV64IDZFH-LABEL: fcvt_h_wu_load:
 ; RV64IDZFH:       # %bb.0:
-; RV64IDZFH-NEXT:    lwu a0, 0(a0)
+; RV64IDZFH-NEXT:    lw a0, 0(a0)
 ; RV64IDZFH-NEXT:    fcvt.h.wu fa0, a0
 ; RV64IDZFH-NEXT:    ret
 ;
@@ -1505,7 +1493,7 @@ define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
 ;
 ; RV64IZDINXZHINX-LABEL: fcvt_h_wu_load:
 ; RV64IZDINXZHINX:       # %bb.0:
-; RV64IZDINXZHINX-NEXT:    lwu a0, 0(a0)
+; RV64IZDINXZHINX-NEXT:    lw a0, 0(a0)
 ; RV64IZDINXZHINX-NEXT:    fcvt.h.wu a0, a0
 ; RV64IZDINXZHINX-NEXT:    ret
 ;
@@ -1518,7 +1506,7 @@ define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
 ;
 ; CHECK64-IZFHMIN-LABEL: fcvt_h_wu_load:
 ; CHECK64-IZFHMIN:       # %bb.0:
-; CHECK64-IZFHMIN-NEXT:    lwu a0, 0(a0)
+; CHECK64-IZFHMIN-NEXT:    lw a0, 0(a0)
 ; CHECK64-IZFHMIN-NEXT:    fcvt.s.wu fa5, a0
 ; CHECK64-IZFHMIN-NEXT:    fcvt.h.s fa0, fa5
 ; CHECK64-IZFHMIN-NEXT:    ret
@@ -1532,7 +1520,7 @@ define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
 ;
 ; CHECK64-IZHINXMIN-LABEL: fcvt_h_wu_load:
 ; CHECK64-IZHINXMIN:       # %bb.0:
-; CHECK64-IZHINXMIN-NEXT:    lwu a0, 0(a0)
+; CHECK64-IZHINXMIN-NEXT:    lw a0, 0(a0)
 ; CHECK64-IZHINXMIN-NEXT:    fcvt.s.wu a0, a0
 ; CHECK64-IZHINXMIN-NEXT:    fcvt.h.s a0, a0
 ; CHECK64-IZHINXMIN-NEXT:    ret
@@ -1546,7 +1534,7 @@ define half @fcvt_h_wu_load(ptr %p) nounwind strictfp {
 ;
 ; CHECK64-IZDINXZHINXMIN-LABEL: fcvt_h_wu_load:
 ; CHECK64-IZDINXZHINXMIN:       # %bb.0:
-; CHECK64-IZDINXZHINXMIN-NEXT:    lwu a0, 0(a0)
+; CHECK64-IZDINXZHINXMIN-NEXT:    lw a0, 0(a0)
 ; CHECK64-IZDINXZHINXMIN-NEXT:    fcvt.s.wu a0, a0
 ; CHECK64-IZDINXZHINXMIN-NEXT:    fcvt.h.s a0, a0
 ; CHECK64-IZDINXZHINXMIN-NEXT:    ret