mirror of
				https://github.com/c64scene-ar/llvm-6502.git
				synced 2025-11-04 05:17:07 +00:00 
			
		
		
		
	computation can be truncated if it is fed by a sext/zext that doesn't have to be exactly equal to the truncation result type. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112285 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			100 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
; RUN: opt < %s -instcombine -S | FileCheck %s
 | 
						|
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 | 
						|
 | 
						|
; Instcombine should be able to eliminate all of these ext casts.
 | 
						|
 | 
						|
declare void @use(i32)
 | 
						|
 | 
						|
define i64 @test1(i64 %a) {
 | 
						|
  %b = trunc i64 %a to i32
 | 
						|
  %c = and i32 %b, 15
 | 
						|
  %d = zext i32 %c to i64
 | 
						|
  call void @use(i32 %b)
 | 
						|
  ret i64 %d
 | 
						|
; CHECK: @test1
 | 
						|
; CHECK: %d = and i64 %a, 15
 | 
						|
; CHECK: ret i64 %d
 | 
						|
}
 | 
						|
define i64 @test2(i64 %a) {
 | 
						|
  %b = trunc i64 %a to i32
 | 
						|
  %c = shl i32 %b, 4
 | 
						|
  %q = ashr i32 %c, 4
 | 
						|
  %d = sext i32 %q to i64
 | 
						|
  call void @use(i32 %b)
 | 
						|
  ret i64 %d
 | 
						|
; CHECK: @test2
 | 
						|
; CHECK: shl i64 %a, 36
 | 
						|
; CHECK: %d = ashr i64 {{.*}}, 36
 | 
						|
; CHECK: ret i64 %d
 | 
						|
}
 | 
						|
define i64 @test3(i64 %a) {
 | 
						|
  %b = trunc i64 %a to i32
 | 
						|
  %c = and i32 %b, 8
 | 
						|
  %d = zext i32 %c to i64
 | 
						|
  call void @use(i32 %b)
 | 
						|
  ret i64 %d
 | 
						|
; CHECK: @test3
 | 
						|
; CHECK: %d = and i64 %a, 8
 | 
						|
; CHECK: ret i64 %d
 | 
						|
}
 | 
						|
define i64 @test4(i64 %a) {
 | 
						|
  %b = trunc i64 %a to i32
 | 
						|
  %c = and i32 %b, 8
 | 
						|
  %x = xor i32 %c, 8
 | 
						|
  %d = zext i32 %x to i64
 | 
						|
  call void @use(i32 %b)
 | 
						|
  ret i64 %d
 | 
						|
; CHECK: @test4
 | 
						|
; CHECK: = and i64 %a, 8
 | 
						|
; CHECK: %d = xor i64 {{.*}}, 8
 | 
						|
; CHECK: ret i64 %d
 | 
						|
}
 | 
						|
 | 
						|
define i32 @test5(i32 %A) {
 | 
						|
  %B = zext i32 %A to i128
 | 
						|
  %C = lshr i128 %B, 16
 | 
						|
  %D = trunc i128 %C to i32
 | 
						|
  ret i32 %D
 | 
						|
; CHECK: @test5
 | 
						|
; CHECK: %C = lshr i32 %A, 16
 | 
						|
; CHECK: ret i32 %C
 | 
						|
}
 | 
						|
 | 
						|
define i32 @test6(i64 %A) {
 | 
						|
  %B = zext i64 %A to i128
 | 
						|
  %C = lshr i128 %B, 32
 | 
						|
  %D = trunc i128 %C to i32
 | 
						|
  ret i32 %D
 | 
						|
; CHECK: @test6
 | 
						|
; CHECK: %C = lshr i64 %A, 32
 | 
						|
; CHECK: %D = trunc i64 %C to i32
 | 
						|
; CHECK: ret i32 %D
 | 
						|
}
 | 
						|
 | 
						|
define i92 @test7(i64 %A) {
 | 
						|
  %B = zext i64 %A to i128
 | 
						|
  %C = lshr i128 %B, 32
 | 
						|
  %D = trunc i128 %C to i92
 | 
						|
  ret i92 %D
 | 
						|
; CHECK: @test7
 | 
						|
; CHECK: %B = zext i64 %A to i92
 | 
						|
; CHECK: %C = lshr i92 %B, 32
 | 
						|
; CHECK: ret i92 %C
 | 
						|
}
 | 
						|
 | 
						|
define i64 @test8(i32 %A, i32 %B) {
 | 
						|
  %tmp38 = zext i32 %A to i128
 | 
						|
  %tmp32 = zext i32 %B to i128
 | 
						|
  %tmp33 = shl i128 %tmp32, 32
 | 
						|
  %ins35 = or i128 %tmp33, %tmp38
 | 
						|
  %tmp42 = trunc i128 %ins35 to i64
 | 
						|
  ret i64 %tmp42
 | 
						|
; CHECK: @test8
 | 
						|
; CHECK:   %tmp38 = zext i32 %A to i64
 | 
						|
; CHECK:   %tmp32 = zext i32 %B to i64
 | 
						|
; CHECK:   %tmp33 = shl i64 %tmp32, 32
 | 
						|
; CHECK:   %ins35 = or i64 %tmp33, %tmp38
 | 
						|
; CHECK:   ret i64 %ins35
 | 
						|
}
 | 
						|
 |