release/20.x: [AArch64] Don't try to custom lower fp16 selects with nofp (#129492)#129546
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tstellar merged 1 commit intollvm:release/20.xfrom Mar 11, 2025
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release/20.x: [AArch64] Don't try to custom lower fp16 selects with nofp (#129492)#129546tstellar merged 1 commit intollvm:release/20.xfrom
tstellar merged 1 commit intollvm:release/20.xfrom
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@ostannard What do you think about merging this PR to the release branch? |
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@llvm/pr-subscribers-backend-aarch64 Author: None (llvmbot) ChangesBackport cb850fe Requested by: @davemgreen Full diff: https://github.com/llvm/llvm-project/pull/129546.diff 2 Files Affected:
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index b5cca88b6b511..a2824d6a8f5af 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -498,8 +498,10 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
setOperationAction(ISD::BR_CC, MVT::f64, Custom);
setOperationAction(ISD::SELECT, MVT::i32, Custom);
setOperationAction(ISD::SELECT, MVT::i64, Custom);
- setOperationAction(ISD::SELECT, MVT::f16, Custom);
- setOperationAction(ISD::SELECT, MVT::bf16, Custom);
+ if (Subtarget->hasFPARMv8()) {
+ setOperationAction(ISD::SELECT, MVT::f16, Custom);
+ setOperationAction(ISD::SELECT, MVT::bf16, Custom);
+ }
setOperationAction(ISD::SELECT, MVT::f32, Custom);
setOperationAction(ISD::SELECT, MVT::f64, Custom);
setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
diff --git a/llvm/test/CodeGen/AArch64/16bit-float-promotion-with-nofp.ll b/llvm/test/CodeGen/AArch64/16bit-float-promotion-with-nofp.ll
index bfe9ab8424bb0..f560420e2c920 100644
--- a/llvm/test/CodeGen/AArch64/16bit-float-promotion-with-nofp.ll
+++ b/llvm/test/CodeGen/AArch64/16bit-float-promotion-with-nofp.ll
@@ -29,3 +29,94 @@ entry:
ret bfloat %0
}
+define double @select_f64(double %a, double %b, i1 %c) {
+; CHECK-LABEL: select_f64:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: tst w2, #0x1
+; CHECK-NEXT: csel x0, x0, x1, ne
+; CHECK-NEXT: ret
+entry:
+ %0 = select i1 %c, double %a, double %b
+ ret double %0
+}
+
+define float @select_f32(float %a, float %b, i1 %c) {
+; CHECK-LABEL: select_f32:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: tst w2, #0x1
+; CHECK-NEXT: csel w0, w0, w1, ne
+; CHECK-NEXT: ret
+entry:
+ %0 = select i1 %c, float %a, float %b
+ ret float %0
+}
+
+define half @select_f16(half %a, half %b, i1 %c) {
+; CHECK-LABEL: select_f16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: tst w2, #0x1
+; CHECK-NEXT: csel w0, w0, w1, ne
+; CHECK-NEXT: ret
+entry:
+ %0 = select i1 %c, half %a, half %b
+ ret half %0
+}
+
+define bfloat @select_bf16(bfloat %a, bfloat %b, i1 %c) {
+; CHECK-LABEL: select_bf16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: tst w2, #0x1
+; CHECK-NEXT: csel w0, w0, w1, ne
+; CHECK-NEXT: ret
+entry:
+ %0 = select i1 %c, bfloat %a, bfloat %b
+ ret bfloat %0
+}
+
+define double @selectcc_f64(double %a, double %b, i32 %d) {
+; CHECK-LABEL: selectcc_f64:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: cmp w2, #0
+; CHECK-NEXT: csel x0, x0, x1, lt
+; CHECK-NEXT: ret
+entry:
+ %c = icmp slt i32 %d, 0
+ %0 = select i1 %c, double %a, double %b
+ ret double %0
+}
+
+define float @selectcc_f32(float %a, float %b, i32 %d) {
+; CHECK-LABEL: selectcc_f32:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: cmp w2, #0
+; CHECK-NEXT: csel w0, w0, w1, lt
+; CHECK-NEXT: ret
+entry:
+ %c = icmp slt i32 %d, 0
+ %0 = select i1 %c, float %a, float %b
+ ret float %0
+}
+
+define half @selectcc_f16(half %a, half %b, i32 %d) {
+; CHECK-LABEL: selectcc_f16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: cmp w2, #0
+; CHECK-NEXT: csel w0, w0, w1, lt
+; CHECK-NEXT: ret
+entry:
+ %c = icmp slt i32 %d, 0
+ %0 = select i1 %c, half %a, half %b
+ ret half %0
+}
+
+define bfloat @selectcc_bf16(bfloat %a, bfloat %b, i32 %d) {
+; CHECK-LABEL: selectcc_bf16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: cmp w2, #0
+; CHECK-NEXT: csel w0, w0, w1, lt
+; CHECK-NEXT: ret
+entry:
+ %c = icmp slt i32 %d, 0
+ %0 = select i1 %c, bfloat %a, bfloat %b
+ ret bfloat %0
+}
|
ostannard
approved these changes
Mar 3, 2025
If we do not have fp then we do not need to try and custom lower fp16 selects. Fixes llvm#129394. (cherry picked from commit cb850fe)
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@davemgreen (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR. |
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Backport cb850fe
Requested by: @davemgreen