Skip to content

Conversation

@arsenm
Copy link
Contributor

@arsenm arsenm commented Oct 31, 2025

No description provided.

Copy link
Contributor Author

arsenm commented Oct 31, 2025

This stack of pull requests is managed by Graphite. Learn more about stacking.

@arsenm arsenm marked this pull request as ready for review October 31, 2025 21:15
@llvmbot
Copy link
Member

llvmbot commented Oct 31, 2025

@llvm/pr-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/165921.diff

1 Files Affected:

  • (added) llvm/test/CodeGen/AMDGPU/umin-sub-to-usubo-select-combine.ll (+236)
diff --git a/llvm/test/CodeGen/AMDGPU/umin-sub-to-usubo-select-combine.ll b/llvm/test/CodeGen/AMDGPU/umin-sub-to-usubo-select-combine.ll
new file mode 100644
index 0000000000000..22e4a24435f12
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/umin-sub-to-usubo-select-combine.ll
@@ -0,0 +1,236 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -mtriple=amdgcn-amd-amdpal -mcpu=gfx900 < %s | FileCheck -check-prefix=GFX9 %s
+; RUN: llc -mtriple=amdgcn-amd-amdpal -mcpu=gfx1100 < %s | FileCheck -check-prefix=GFX11 %s
+
+define i16 @v_underflow_compare_fold_i16(i16 %a, i16 %b) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i16:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_u16_e32 v1, v0, v1
+; GFX9-NEXT:    v_min_u16_e32 v0, v1, v0
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i16:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_nc_u16 v0.h, v0.l, v1.l
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
+; GFX11-NEXT:    v_min_u16 v0.l, v0.h, v0.l
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i16 %a, %b
+  %cond = call i16 @llvm.umin.i16(i16 %sub, i16 %a)
+  ret i16 %cond
+}
+
+define i32 @v_underflow_compare_fold_i32(i32 %a, i32 %b) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i32:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_u32_e32 v1, v0, v1
+; GFX9-NEXT:    v_min_u32_e32 v0, v1, v0
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i32:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_nc_u32_e32 v1, v0, v1
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
+; GFX11-NEXT:    v_min_u32_e32 v0, v1, v0
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i32 %a, %b
+  %cond = call i32 @llvm.umin.i32(i32 %sub, i32 %a)
+  ret i32 %cond
+}
+
+define i32 @v_underflow_compare_fold_i32_commute(i32 %a, i32 %b) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i32_commute:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_u32_e32 v1, v0, v1
+; GFX9-NEXT:    v_min_u32_e32 v0, v0, v1
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i32_commute:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_nc_u32_e32 v1, v0, v1
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
+; GFX11-NEXT:    v_min_u32_e32 v0, v0, v1
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i32 %a, %b
+  %cond = call i32 @llvm.umin.i32(i32 %a, i32 %sub)
+  ret i32 %cond
+}
+
+define i32 @v_underflow_compare_fold_i32_multi_use(i32 %a, i32 %b, ptr addrspace(1) %ptr) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i32_multi_use:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_u32_e32 v1, v0, v1
+; GFX9-NEXT:    v_min_u32_e32 v0, v1, v0
+; GFX9-NEXT:    global_store_dword v[2:3], v1, off
+; GFX9-NEXT:    s_waitcnt vmcnt(0)
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i32_multi_use:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_nc_u32_e32 v1, v0, v1
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
+; GFX11-NEXT:    v_min_u32_e32 v0, v1, v0
+; GFX11-NEXT:    global_store_b32 v[2:3], v1, off
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i32 %a, %b
+  store i32 %sub, ptr addrspace(1) %ptr
+  %cond = call i32 @llvm.umin.i32(i32 %sub, i32 %a)
+  ret i32 %cond
+}
+
+define i64 @v_underflow_compare_fold_i64(i64 %a, i64 %b) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i64:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_co_u32_e32 v2, vcc, v0, v2
+; GFX9-NEXT:    v_subb_co_u32_e32 v3, vcc, v1, v3, vcc
+; GFX9-NEXT:    v_cmp_lt_u64_e32 vcc, v[2:3], v[0:1]
+; GFX9-NEXT:    v_cndmask_b32_e32 v0, v0, v2, vcc
+; GFX9-NEXT:    v_cndmask_b32_e32 v1, v1, v3, vcc
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i64:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_co_u32 v2, vcc_lo, v0, v2
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1) | instskip(NEXT) | instid1(VALU_DEP_1)
+; GFX11-NEXT:    v_sub_co_ci_u32_e64 v3, null, v1, v3, vcc_lo
+; GFX11-NEXT:    v_cmp_lt_u64_e32 vcc_lo, v[2:3], v[0:1]
+; GFX11-NEXT:    v_dual_cndmask_b32 v0, v0, v2 :: v_dual_cndmask_b32 v1, v1, v3
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i64 %a, %b
+  %cond = call i64 @llvm.umin.i64(i64 %sub, i64 %a)
+  ret i64 %cond
+}
+
+define i64 @v_underflow_compare_fold_i64_commute(i64 %a, i64 %b) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i64_commute:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_co_u32_e32 v2, vcc, v0, v2
+; GFX9-NEXT:    v_subb_co_u32_e32 v3, vcc, v1, v3, vcc
+; GFX9-NEXT:    v_cmp_lt_u64_e32 vcc, v[0:1], v[2:3]
+; GFX9-NEXT:    v_cndmask_b32_e32 v0, v2, v0, vcc
+; GFX9-NEXT:    v_cndmask_b32_e32 v1, v3, v1, vcc
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i64_commute:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_co_u32 v2, vcc_lo, v0, v2
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1) | instskip(NEXT) | instid1(VALU_DEP_1)
+; GFX11-NEXT:    v_sub_co_ci_u32_e64 v3, null, v1, v3, vcc_lo
+; GFX11-NEXT:    v_cmp_lt_u64_e32 vcc_lo, v[0:1], v[2:3]
+; GFX11-NEXT:    v_dual_cndmask_b32 v0, v2, v0 :: v_dual_cndmask_b32 v1, v3, v1
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i64 %a, %b
+  %cond = call i64 @llvm.umin.i64(i64 %a, i64 %sub)
+  ret i64 %cond
+}
+
+define i64 @v_underflow_compare_fold_i64_multi_use(i64 %a, i64 %b, ptr addrspace(1) %ptr) #0 {
+; GFX9-LABEL: v_underflow_compare_fold_i64_multi_use:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX9-NEXT:    v_sub_co_u32_e32 v2, vcc, v0, v2
+; GFX9-NEXT:    v_subb_co_u32_e32 v3, vcc, v1, v3, vcc
+; GFX9-NEXT:    v_cmp_lt_u64_e32 vcc, v[2:3], v[0:1]
+; GFX9-NEXT:    global_store_dwordx2 v[4:5], v[2:3], off
+; GFX9-NEXT:    v_cndmask_b32_e32 v0, v0, v2, vcc
+; GFX9-NEXT:    v_cndmask_b32_e32 v1, v1, v3, vcc
+; GFX9-NEXT:    s_waitcnt vmcnt(0)
+; GFX9-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX11-LABEL: v_underflow_compare_fold_i64_multi_use:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    v_sub_co_u32 v2, vcc_lo, v0, v2
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1) | instskip(NEXT) | instid1(VALU_DEP_1)
+; GFX11-NEXT:    v_sub_co_ci_u32_e64 v3, null, v1, v3, vcc_lo
+; GFX11-NEXT:    v_cmp_lt_u64_e32 vcc_lo, v[2:3], v[0:1]
+; GFX11-NEXT:    global_store_b64 v[4:5], v[2:3], off
+; GFX11-NEXT:    v_dual_cndmask_b32 v0, v0, v2 :: v_dual_cndmask_b32 v1, v1, v3
+; GFX11-NEXT:    s_setpc_b64 s[30:31]
+  %sub = sub i64 %a, %b
+  store i64 %sub, ptr addrspace(1) %ptr
+  %cond = call i64 @llvm.umin.i64(i64 %sub, i64 %a)
+  ret i64 %cond
+}
+
+define amdgpu_ps i16 @s_underflow_compare_fold_i16(i16 inreg %a, i16 inreg %b) #0 {
+; GFX9-LABEL: s_underflow_compare_fold_i16:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_sub_i32 s1, s0, s1
+; GFX9-NEXT:    s_and_b32 s0, 0xffff, s0
+; GFX9-NEXT:    s_and_b32 s1, s1, 0xffff
+; GFX9-NEXT:    s_min_u32 s0, s1, s0
+; GFX9-NEXT:    ; return to shader part epilog
+;
+; GFX11-LABEL: s_underflow_compare_fold_i16:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_sub_i32 s1, s0, s1
+; GFX11-NEXT:    s_and_b32 s0, 0xffff, s0
+; GFX11-NEXT:    s_and_b32 s1, s1, 0xffff
+; GFX11-NEXT:    s_delay_alu instid0(SALU_CYCLE_1)
+; GFX11-NEXT:    s_min_u32 s0, s1, s0
+; GFX11-NEXT:    ; return to shader part epilog
+  %sub = sub i16 %a, %b
+  %cond = call i16 @llvm.umin.i16(i16 %sub, i16 %a)
+  ret i16 %cond
+}
+
+define amdgpu_ps i32 @s_underflow_compare_fold_i32(i32 inreg %a, i32 inreg %b) #0 {
+; GFX9-LABEL: s_underflow_compare_fold_i32:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_sub_i32 s1, s0, s1
+; GFX9-NEXT:    s_min_u32 s0, s1, s0
+; GFX9-NEXT:    ; return to shader part epilog
+;
+; GFX11-LABEL: s_underflow_compare_fold_i32:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_sub_i32 s1, s0, s1
+; GFX11-NEXT:    s_delay_alu instid0(SALU_CYCLE_1)
+; GFX11-NEXT:    s_min_u32 s0, s1, s0
+; GFX11-NEXT:    ; return to shader part epilog
+  %sub = sub i32 %a, %b
+  %cond = call i32 @llvm.umin.i32(i32 %sub, i32 %a)
+  ret i32 %cond
+}
+
+define amdgpu_ps i64 @s_underflow_compare_fold_i64(i64 inreg %a, i64 inreg %b) #0 {
+; GFX9-LABEL: s_underflow_compare_fold_i64:
+; GFX9:       ; %bb.0:
+; GFX9-NEXT:    s_sub_u32 s2, s0, s2
+; GFX9-NEXT:    v_mov_b32_e32 v0, s0
+; GFX9-NEXT:    s_subb_u32 s3, s1, s3
+; GFX9-NEXT:    v_mov_b32_e32 v1, s1
+; GFX9-NEXT:    v_cmp_lt_u64_e32 vcc, s[2:3], v[0:1]
+; GFX9-NEXT:    s_and_b64 s[4:5], vcc, exec
+; GFX9-NEXT:    s_cselect_b32 s1, s3, s1
+; GFX9-NEXT:    s_cselect_b32 s0, s2, s0
+; GFX9-NEXT:    ; return to shader part epilog
+;
+; GFX11-LABEL: s_underflow_compare_fold_i64:
+; GFX11:       ; %bb.0:
+; GFX11-NEXT:    s_sub_u32 s2, s0, s2
+; GFX11-NEXT:    s_subb_u32 s3, s1, s3
+; GFX11-NEXT:    s_delay_alu instid0(SALU_CYCLE_1)
+; GFX11-NEXT:    v_cmp_lt_u64_e64 s4, s[2:3], s[0:1]
+; GFX11-NEXT:    s_and_b32 s4, s4, exec_lo
+; GFX11-NEXT:    s_cselect_b32 s0, s2, s0
+; GFX11-NEXT:    s_cselect_b32 s1, s3, s1
+; GFX11-NEXT:    ; return to shader part epilog
+  %sub = sub i64 %a, %b
+  %cond = call i64 @llvm.umin.i64(i64 %sub, i64 %a)
+  ret i64 %cond
+}
+
+attributes #0 = { nounwind }

@arsenm arsenm enabled auto-merge (squash) October 31, 2025 21:20
@arsenm arsenm merged commit cf829cc into main Oct 31, 2025
11 of 13 checks passed
@arsenm arsenm deleted the users/arsenm/amdgpu/add-tests-pr161651 branch October 31, 2025 21:50
DEBADRIBASAK pushed a commit to DEBADRIBASAK/llvm-project that referenced this pull request Nov 3, 2025
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants