maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/CodeGen/PowerPC/fp-int128-fp-combine.ll

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

43 lines
1.1 KiB
LLVM
Raw Normal View History

[PPC] Avoid incorrect fp-i128-fp lowering. Summary: Fix an issue that's similar to what D41411 fixed: float(__int128(float_var)) shouldn't be optimized to xscvdpsxds + xscvsxdsp, as they mean (float)(int64_t)float_var. Reviewers: jtony, hfinkel, echristo Subscribers: sanjoy, nemanjai, hiraditya, llvm-commits, kbarton Differential Revision: https://reviews.llvm.org/D42400 llvm-svn: 323270
2018-01-24 06:06:57 +08:00
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -O0 -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s
; xscvdpsxds should NOT be emitted, since it saturates the result down to i64.
[DAGCombiner] restrict (float)((int) f) --> ftrunc with no-signed-zeros As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc can produce -0.0 where the original code does not: #include <stdio.h> int main(int argc) { float x; x = -0.8 * argc; printf("%f\n", (float)((int)x)); return 0; } $ clang -O0 -mavx fp.c ; ./a.out 0.000000 $ clang -O1 -mavx fp.c ; ./a.out -0.000000 Ideally, we'd use IR/node flags to predicate the transform, but the IR parser doesn't currently allow fast-math-flags on the cast instructions. So for now, just use the function attribute that corresponds to clang's "-fno-signed-zeros" option. Differential Revision: https://reviews.llvm.org/D48085 llvm-svn: 335761
2018-06-28 02:16:40 +08:00
; We can't use friz here because it may return -0.0 where the original code doesn't.
[PowerPC][NFC] Avoid checking non-relevant .cfi instructions Summary: This is brought up in https://reviews.llvm.org/D64662?id=209923#inline-599490 CFI information are non-relevant to quite some testcases, we should get rid of checking them when its unecessary. This patch avoid generating cfi info in testcases that are not testing prolog/epilog or exception handling. Reviewers: kbarton, hfinkel, nemanjai, #powerpc Reviewed By: hfinkel Subscribers: MaskRay, shchenz, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67016 llvm-svn: 370505
2019-08-31 03:24:25 +08:00
define float @f_i128_f(float %v) nounwind {
[PPC] Avoid incorrect fp-i128-fp lowering. Summary: Fix an issue that's similar to what D41411 fixed: float(__int128(float_var)) shouldn't be optimized to xscvdpsxds + xscvsxdsp, as they mean (float)(int64_t)float_var. Reviewers: jtony, hfinkel, echristo Subscribers: sanjoy, nemanjai, hiraditya, llvm-commits, kbarton Differential Revision: https://reviews.llvm.org/D42400 llvm-svn: 323270
2018-01-24 06:06:57 +08:00
; CHECK-LABEL: f_i128_f:
; CHECK: # %bb.0: # %entry
[DAGCombiner] restrict (float)((int) f) --> ftrunc with no-signed-zeros As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc can produce -0.0 where the original code does not: #include <stdio.h> int main(int argc) { float x; x = -0.8 * argc; printf("%f\n", (float)((int)x)); return 0; } $ clang -O0 -mavx fp.c ; ./a.out 0.000000 $ clang -O1 -mavx fp.c ; ./a.out -0.000000 Ideally, we'd use IR/node flags to predicate the transform, but the IR parser doesn't currently allow fast-math-flags on the cast instructions. So for now, just use the function attribute that corresponds to clang's "-fno-signed-zeros" option. Differential Revision: https://reviews.llvm.org/D48085 llvm-svn: 335761
2018-06-28 02:16:40 +08:00
; CHECK-NEXT: mflr 0
; CHECK-NEXT: std 0, 16(1)
; CHECK-NEXT: stdu 1, -32(1)
; CHECK-NEXT: bl __fixsfti
; CHECK-NEXT: nop
; CHECK-NEXT: bl __floattisf
; CHECK-NEXT: nop
; CHECK-NEXT: addi 1, 1, 32
; CHECK-NEXT: ld 0, 16(1)
; CHECK-NEXT: mtlr 0
; CHECK-NEXT: blr
entry:
%a = fptosi float %v to i128
%b = sitofp i128 %a to float
ret float %b
}
; NSZ, so it's safe to friz.
define float @f_i128_fi_nsz(float %v) #0 {
; CHECK-LABEL: f_i128_fi_nsz:
; CHECK: # %bb.0: # %entry
RegAllocFast: Remove early selection loop, the spill calculation will report cost 0 anyway for free regs The 2nd loop calculates spill costs but reports free registers as cost 0 anyway, so there is little benefit from having a separate early loop. Surprisingly this is not NFC, as many register are marked regDisabled so the first loop often picks up later registers unnecessarily instead of the first one available in the allocation order... Patch by Matthias Braun llvm-svn: 356499
2019-03-20 03:01:34 +08:00
; CHECK-NEXT: friz 0, 1
; CHECK-NEXT: fmr 1, 0
[PPC] Avoid incorrect fp-i128-fp lowering. Summary: Fix an issue that's similar to what D41411 fixed: float(__int128(float_var)) shouldn't be optimized to xscvdpsxds + xscvsxdsp, as they mean (float)(int64_t)float_var. Reviewers: jtony, hfinkel, echristo Subscribers: sanjoy, nemanjai, hiraditya, llvm-commits, kbarton Differential Revision: https://reviews.llvm.org/D42400 llvm-svn: 323270
2018-01-24 06:06:57 +08:00
; CHECK-NEXT: blr
entry:
%a = fptosi float %v to i128
%b = sitofp i128 %a to float
ret float %b
}
[DAGCombiner] restrict (float)((int) f) --> ftrunc with no-signed-zeros As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc can produce -0.0 where the original code does not: #include <stdio.h> int main(int argc) { float x; x = -0.8 * argc; printf("%f\n", (float)((int)x)); return 0; } $ clang -O0 -mavx fp.c ; ./a.out 0.000000 $ clang -O1 -mavx fp.c ; ./a.out -0.000000 Ideally, we'd use IR/node flags to predicate the transform, but the IR parser doesn't currently allow fast-math-flags on the cast instructions. So for now, just use the function attribute that corresponds to clang's "-fno-signed-zeros" option. Differential Revision: https://reviews.llvm.org/D48085 llvm-svn: 335761
2018-06-28 02:16:40 +08:00
attributes #0 = { "no-signed-zeros-fp-math"="true" }